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Python coding interview challenges

451 points by sconxu 10y ago

v3gas 10y ago
Thanks!
gigatexal 10y ago
The advent of all of these coding challenge excercises makes not being able to do one in an interview a real show stopper. Glad there's all this material to learn from.
- JamesMcMinn 10y ago
  Not really. If anything it just makes coding challenges useless for distinguishing between people who can think, and people who can regurgitate. It's one thing to "know" how to balance a binary tree because you've read up on and practiced the most common challenges - it's something else entirely to actually think through and understand a problem, then come up with a solution. I'd much rather have someone who can describe the edge cases and the complexity of a problem but get the final solution slightly wrong (but hey, the know the edge cases so can write tests for it, right?), than someone who can regurgitate code they've written before without really understanding it.
  - gigatexal 10y ago
    Sure I agree as well. That there are so many resources and tools available to answer these coding challenges that if for whatever reason such a challenge was presented the minimum is to be able to answer thr challenge. Going beyond would be to know when to use such a data structure or its inherent strengths and weaknesses etc.
    - bigmanwalter 10y ago
      Unless someone can't study these things because they're too busy writing real-world code.
      - gigatexal 10y ago
        Which is why I think companies doing less whiteboard interviews and more real world coding tests make more sense. I think one could understand the limitations of a linked list and still use the built in data structures and be really competent.
  - eriknstr 10y ago
    >It's one thing to "know" how to balance a binary tree because you've read up on and practiced the most common challenges - it's something else entirely to actually think through and understand a problem, then come up with a solution. There are too many things to know in the world in order to be able to know them all as deeply as we wish. For the things that we can get away with knowing the most common aspects of, time might be better spent elsewhere than to learn more about that thing.
- bogomipz 10y ago
  It's really amazing a whole industry has now sprouted up around hacking the interview process - you have interview boot camps, specific books about cracking the coding interview, mock interviews services with actual S.V engineers. As long as you have memorized how to reverse the last k elements of a doubly linked list you are probably a safe hire.
nickpeterson 10y ago
"Before we hire you, we first need you to outwit this burmese python..."
- JamesMcMinn 10y ago
  Honestly, I think you'd learn more about a potential hire that way than by presenting them with these sort of challenges.
  - nickpeterson 10y ago
    "We see you're familiar with compression but how about pandas?"
    - dr_zoidberg 10y ago
      I fear the part of the interview that gets into spiders for web scraping...
- riebschlager 10y ago
  I'd rather take my chances with a snake than trying to solve "Add two integers without using + or -".
  - brianwawok 10y ago
    sum([5,6]) ?
    - emidln 10y ago
      Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 2, in one_true_addition_test_case AssertionError The "correct" answer according to my pet parrot is (5).__add__(6). Of course, as per real-life, "correct" is usually just an aspect of if you find the interviewer's solution instead of whether your solution is actually correct. Better luck next time!
    - 10y ago
digitalsushi 10y ago
I'm a C+/B- developer. I've been doing this stuff for touching two decades, and these questions gave me a prickly sweat down my back. There is a part of me that feels very lucky to have plopped onto the Earth right when I did, before there was an organized process to weed me out. I'm entrenched enough that interviews are generally just culture fit interviews. I think I'd need ulcer medicine to get a job with no reputation.
- JamesMcMinn 10y ago
  How often have you had to code up solutions to any of these challenges in the last two decades? These sort of challenges are great for learning some of the theory behind computer science and getting you thinking, but they're not a useful part of the interview process imo.
  - collyw 10y ago
    Exactly. I am pretty sure there is a (well tested) library out there to do those things.
    - canttestthis 10y ago
      At some jobs we make the libraries you use to solve those problems. These interview questions test very basic CS concepts and many of them are essentially just extremely watered down versions of real life problems. I can teach a dev how to Google for libraries, I can't teach him basic CS concepts. I would much rather hire for the latter. In fact this whole thread makes me uncomfortable. I wouldn't want to work with anyone who gets nervous when told to reverse a linked list.
      - collyw 10y ago
        Sure, but those jobs are few and far between. If you are indeed writing that sort of code, then it makes complete sense to test people on that, but the vast majority of jobs using this style of testing are not.
bigmanwalter 10y ago
I don't understand code challenges. Can you even program without Google and Stack Overflow anymore? And god-forbid being experienced in a dozen frameworks and libraries if it's not the exact combination the company uses.
- problems 10y ago
  Yes, you're expected to be able to write basic stuff like most of these challenges without Google or StackOverflow. There are some however here that you really shouldn't be, like remembering specific algorithms - if you're just memorizing 20 different sorting algorithm's exactly implementation, clearly that's not producing much if any value for you. If someone however was to give you this Algorithm section https://nbviewer.jupyter.org/github/donnemartin/interactive-coding-challenges/blob/master/sorting_searching/merge_sort/merge_sort_solution.ipynb#Algorithm https://nbviewer.jupyter.org/github/donnemartin/interactive-... and tell you to implement it, that would prove whether you had the skills needed to properly use Google and StackOverflow for anything but a direct copy+paste and could be a very good test for a programmer. Basic data structures, knowing when to apply them and how to solve fairly straightforward challenges like "does this string contain any duplicate characters" when you have full use of Python's builtin data structures are completely fair interview questions in my opinion. Just picking 1 or 2 of these questions that seems vaguely related to your work is enough, combined with asking some basic technical stuff like "What's the difference between a class and an object?" can weed out a shocking number of people, showing they don't even have conversationally useful knowledge about a topic.
  - jacquesm 10y ago
    I've been coding for 4 decades. There are so many different standard libraries and function calls to remember that only the people that are one-trick ponies (one ecosystem, deep knowledge) are going to be able to do the majority of these without an outside reference. And those are exactly the people you would not want for a job because they would most likely not have the flexibility to shift away from that ecosystem if there was a need because it would take them forever to get up to speed. It's much better to know how to use outside references efficiently and to be able to 'swap stacks' in a couple of weeks than it is to be an expert in some language that could very well be obsolete, and that's assuming that there are many jobs left today where deep knowledge of only one ecosystem will get the job done. The time when you could spend 4 years learning a specific library and language and then make a career out of that is long long gone. What we have today is more akin to enormous libraries sitting on fairly rickety narrow foundations where - if you're lucky - the documentation of that library is relatively good, and the half-life of the whole thing is measured in months, a year at best. Today you work in Python, 3 months from now in Go and a another 6 months after that it will be JavaScript, typescript, clojurescript, coffeescript or <insert your flavor here>. So, you want to have your problem programmed in Assembler, C, C++, Python, PHP, BASIC (name your dialect), JavaScript, Erlang, Python or I don't care how many other languages that you care to name I'll accept the challenge. But I won't cut off my external memory bank in order to prove that that is something I can do. (Well, truth be told I probably can do it in a couple of the above but that's mostly because there was a time when the world moved slow enough that you could actually invest a couple of years, but these days it is much better to know how to leverage open source and google than it is to know the gritty little bits of whatever language is in flavor this week.) Of course, if you are looking for 'javascript programmers' it is fair to ask some questions about javascript. But in my experience it is a lot more efficient to search for programming talent and good debugging and writing skills irrespective of what language they are currently trained in. Languages are a means to an end, programming is the skill you want, not 'a particular language programmer'.
RodericDay 10y ago
This feels way over-engineered. I just want to click and jump into a challenge, Project Euler stye. Every single page is overflowing with "Table of Contents", screenshots, code snippets, etc.
TuringNYC 10y ago
From what hear about some startups, the challenges are for the general candidate pipelines the company wants to weed out w/o fearing legal repercussions. The inside-track, friends, and frat candidates often get to skip right through the process or have copies of the problems/answers from insiders. (Illusion of merit.)
- tedmiston 10y ago
  I think this view is a little bit cynical. Hiring your friends which usually happens in the early stages is often more about having worked with them before or having them come in based on a recommendation / knowing they're a culture fit ahead of time etc. It's a way for small startups to spend less time on hiring, and increase their chances of getting talent that they couldn't necessarily attract on the broader market in the early stages.
  - TuringNYC 10y ago
    I appreciate the feedback and you raise good points. However, i'm curious what purpose many of these exams serve...some guesses: - Because it is actually a good predictor of job success (does anyone think this is the case for anything but a handful of job roles?) - To be adding a hurdle to target those who really want the job (downside: it also adds a hurdle to top-notch gainfully employed people who dont have time to study for such exams) - Another is they just need something to reduce an otherwise overqualified pool of already qualified candidates (fair point, but at the risk of losing out candidates from concern one above.) - Legal risk mitigation -- add a quantitative measure to show a facade of merit and process. TBH, I have never been on the hiring side at a small firm, so I don't know. But I have seen several things: 1. People recruiting me to Amazon and practically giving me the exam questions (I declined mostly due to location) Same thing at two other firms (perhaps to get referral bonuses?) 2. An H1B process that is by-the-book correct yet entirely against the spirit of the program. 3. Tons of interviews, screenings, etc at big firms just to justify an already-decided inside candidate. This I witnessed firsthand and makes me really upset because of all the candidate time they waste and the false hope they give to people who were never in the running to being with.
- 10y ago
sparkling 10y ago
Semi off-topic, but i am curious. How much of CS fundamentals do you expect a backend (or fullstack) developer to recite in an job interview? I did all CS theory stuff many years ago at university, but i could not pass a interview test full with these CS basics. Isn't it far more important to know how to design a modern, maintainable, scalable web application? Know how an when to cache stuff. How to design a API. How to integrate with third party APIs. How to setup logging. How to sanitize data and other common security problems. How to setup test/build/deploy structures. Et cetera, you get the point. If, while building a web application, i encounter a "big data"/"data processing" problem, i will find a appropriate solution using CS best practices. But hell, i would struggle to implement a simple array sorting algorithm under pressure.
- thecardcheat 10y ago
  What matters is how much the company you want to work for expects you to whiteboard or code to pass their screens. Big company? You almost certainly need to have your CS challenge question toolbox full. Smaller company? Many follow the big company interview methodology, but some don't, so more likely you can get away with not breaking the spine on your Cracking the Coding Interview.
- brianwawok 10y ago
  I think if you are fresh out of college, cute little algo challenges are OK.. because a) You should have just learned it b) You don't have years of experience with 12 languages Anything past fresh college grad and they are pretty dumb...
- stuaxo 10y ago
  As a fullstack developer most of these things are not needed. Having a good understanding of what is optimal is good, but you shouldn't have to be able to recite all the big O notation. Funnily enough none of the tests I've had ever talk about relevant things like data normalisation / de-normalisation or anything that will be used in the project.
  - collyw 10y ago
southphillyman 10y ago
I really appreciate the effort that went in to this. This is a perhaps the most thorough hand holding through a "Cracking the Code Interview" regimen I've seen thus far.
iamspoilt 10y ago
Thank you for this! Cheers!
cauterized 10y ago
I see these challenges as a great way for excellent experienced developers to weed out incompetent companies. I'm a kick-ass get-things-done full-stack web engineer. I've never had to deal with one of these sorts of problems in my day to day work; and if I did, I'd just find an existing, tested, stable library that already handled them. A company that needs someone to solve these sorts of problems doesn't want me on their team in the first place, nor would I thrive there. A company that just needs to build damn good web apps is losing out by using these sorts of questions in their interviews. The best interview challenge I've had (actually, it was a take-home, with discussion in the interview proper) was about designing code for re-use and extension. It was a great indicator of the company's practical and mature approach to engineering, and of what they really wanted this hire to accomplish.
- humanrebar 10y ago
  I agree 95%. However, inevitably there will be a developer that will want to implement a trie for reasons. It's hard to be able to reason with her (or technical leadership when appealing the decision) when advocating for an off the shelf alternative if you can't explain why this isn't a brand new problem. On the flip side, one actually does need to create a new data structure on occasion, and obviously there we would want to be able to implement the common alternatives. Anyway, it's complicated. Especially when hiring for technical leadership.
  - vonmoltke 10y ago
    If I need to convince another developer that a particular path is well-worn and that they are drifting towards NIH syndrome I have the benefit of time to develop an argument and resources with which to do so. I do not have 45 minutes, no resources, and just a whiteboard. To pre-counter an expected objection, if your company makes significant decisions like that in a single 45-minute (or any length, really) meeting you need to change your design process, not your hiring process.
    - humanrebar 10y ago
      > I have the benefit of time to develop an argument and resources with which to do so. One would assume so. That's not always the case in my experience. Improvisational discussion of design tradeoffs and costs happen a lot. YMMV, I guess. Though I agree that no-google, closed-book, no-IDE whiteboard development is very unnatural. > ...if your company makes significant decisions like that in a single 45-minute (or any length, really) meeting you need to change your design process, not your hiring process. I'd agree with that, but design processes on the whole tend to more dysfunctional than organizations realize. There's still a lot stuff running on deprecated OSs, dead languages, and mountains of technical debt.
throwaway2016a 10y ago
In a way I prefer this to "how many ping pong balls can fit in a school bus" that was all the rage in the 90s and early 2000s. But... man... I have a computer science degree, I've been coding for 20 years, and I've held (and kept) a CTO role at two mid-sized startup companies. Currently I'm considering looking for a job at a larger company (where I wouldn't be CTO but I'd be hopefully paid more) and these kind of questions make me think I need to almost go back to school before I can start interviewing. When did it get to the point where we need to read thick books on programming interviews and spend hundreds of hours on HackerRank practicing algorithms to get a job where we probably won't use any of those day-to-day? Edit: For fun the other day I decided to code a linked-list from scratch in C and it took me a half-hour plus... and I have known that data structure for decades. I can't imagine doing a harder problem under the pressure of being an interview.
- sparkling 10y ago
  I agree. To find out if one is actually competent, open questions that allow the candidate to elaborate on his previous problem solving experience are much more useful. Some examples: 1) Explain how and why you would implement authentication on a HTTP API. What other authentication methods do you know and why would you not use them? 2) Tell us about a scaling-up challenge/problem you had on your last application and how you solved it. 3) What technology stack would you use for a browser-based P2P file sharing application? 4) Name a library you recently discovered. What problem did it solve? 5) What mobile app on your phone right now has a bad user experience in your opinion? How would you make it better?
- dahart 10y ago
  Keep in mind that, because the number of programmers is increasing, the majority of them are fresh out of school or close to it. Algorithms interviews are largely designed for interviewing people who don't have much experience, so they're skewed toward testing what people learned in school. If after 2 CTO roles you interview for a job and they ask you to write a linked list algorithm, then would you want to work there? I mean you might, but that alone should at least beg the question. If they're not asking you how you'd manage a team of smart but stubborn coders or structure their company's software architecture and services to be more reliable, then they certainly aren't paying much attention to you or what your strengths and experience are. Or they simply don't know how to hire an experienced person, which signals that they don't know what to do with an experienced person once hired. Also, it would take the vast majority of great coders at least a half hour to code a linked-list from scratch in C and get it right, depending on what you're doing. So don't worry.
kclay 10y ago
I recently tried for the second time to apply to some agency type place. I have 10yrs of coding, worked with big data, have done micro coding( developed protocols for vending machine transactions), done frontend and backend small and large scale. But this place had 3 of these type of challenges that you had 1hr 30mins to complete all of them. I'm sorry, most of this stuff you will NOT find in any job unless its some specialty. For an backend/angular/react developer you will not find this at all. I feel that companies that do this are out of touch with the correct way to find candidates. But on the second hand I also see why they do this since programming has became so much popular now a days.
- ethbro 10y ago
  In the same way that nobody ever got fired for suggesting IBM, I imagine there's a lot of HR / tech hiring apeing MS/Google/FB. Even if it makes no sense in their business development context.
falcolas 10y ago
Somewhat of a tangent, but that "Distributed design" document gives me hives - with the lack of lines from "write" or "async write" back to the readers or cache. The taming of stale data would be a nightmare to manage when it suddenly starts to matter. Also, where's the completed response caching layer? Nothing destroys performance (and hikes costs) like having to recompute every page response from raw data. And that doesn't even touch my annoyance at shoehorning "federated architecture" to mean "sharding with a different algorithm".
swalsh 10y ago
This feels like hiring a new rough framer by asking him to carve a cabriole leg.
agentultra 10y ago
This is great! Having an integrated environment with the tests included and solutions in a separate notebook is quite valuable for training to pass technical interviews. I see a lot of people posting about how they dislike the technical interviewing process. The sentiment seems to be that for a certain class of popular developer role it's entirely unlikely that they will ever need to remember how to implement a heap or red-black tree to be effective at their job... so why use problems like this in an interview? I think these sorts of questions should be used by teams that want to set the minimum standards on the team. I'm reminded of a rule used at the Recurse Centre: never feign surprise when someone asks a question (I paraphrase). The idea is that if someone asks you a question about something you think is fundamental, like Bash for example, don't immediately feign surprise and say, "You don't know bash?" It's not helpful. Instead take it as an opportunity to teach them something awesome. However this doesn't generally work in a professional setting where you're required to know Bash in order to function at your job. If on my team we're responsible for the operation and maintenance of several millions of dollars worth of infrastructure that runs our customers' applications then there are certain minimum requirements for operating effectively within this team. I expect you would know Bash at a minimum. I should also expect you to know the network stack of the OS we deploy on, how TCP works, what a hypervisor is, etc. We may write most of our application code in a high-level language that abstracts these details away but that doesn't preclude you from understanding them. It's just a convenient tool. You have to know how to manage complexity and avoid premature pessimization in order to be effective and that means you will be interviewed using technical questions to screen for that minimum level of knowledge. However I think most companies do tend to use this tool poorly. I've interviewed with startups that build consumer web applications that ask questions about radix sort and k-d trees. That's what I call, overkill. This trap is easy to fall into if your motto is something glib and banal like, "We only hire the best." If you don't quantify what "best" is you're just going to negatively filter out potential candidates and hire on bias. You have to scale the screening process to only test for that minimum competency and choose how much risk you want to take in teaching new hires. If I'm hiring a more junior developer to our team I expect that we're going to mentor that person and make them a better engineer by working with us. They can ask questions that may be outside of our minimum standard. However if I'm hiring for a team-lead position I'm much more likely to not accept a candidate who cannot fly through our screening process. Working with them is going to be difficult and if it's 3 in the morning and they're causing more problems than fixing because they don't know how the TCP re-transmission protocol works then we're going to have a problem. The conclusion of all this is: tweak the screening process to set the minimum standards required for effective communication on the team. Don't set the bar unnecessarily high: define what the bar should be and assess the risk of mentoring junior developers. You need a good mix across the spectrum for an effective team.
dec0dedab0de 10y ago
looking at code that re-implements features of the language is annoying enough, but having it be so non-pythonic is just painful.
optimuspaul 10y ago
I have always seen the interview process as a an opportunity to understand how the other person thinks. These questions may do that to some extent but they limit it in ways that make it almost mechanical. I personally find "What is your favorite programming language?" or "What systems architecture to you find more compelling?" to be far more valuable. It gives some insight into their commitment to the trade and gives you an opportunity to make it a conversation to dive into their reasoning process and depth of knowledge about a topic. I think it's far easier to weed out the fakers if they can't express why Erlang is interesting to them than for them to tell you how to implement a linked list which is very easy to google and memorize(but won't necessarily prove any skill).
daenz 10y ago
Thanks for this. Just a mild constructive criticism: not sure how useful the Anki deck is. One thing to keep in mind when constructing cards is keeping the information very short. As it stands, there's no way to really remember the flip side of the card. Aside from that, really solid info!
prashnts 10y ago
I've been using Python (among others) at work close to 3 years now. I get these challenges and problems, however, I don't find the solutions here "pythonic". I guess it depends upon the job criteria, but the code here [1], for example, is not a great demonstration of _Python_ language skills. It is a good demonstration that the person knows Mathematics, but if someone is interviewing for a Python dev, it's not what they should be looking for. [1] https://nbviewer.jupyter.org/github/donnemartin/interactive-coding-challenges/blob/master/online_judges/license_key/format_license_key_solution.ipynb#Code https://nbviewer.jupyter.org/github/donnemartin/interactive-...
- danielvinson 10y ago
  That was my reaction also. If a junior engineer asked me to review that code, I would ask them to refactor in a way that is more maintainable.
didip 10y ago
These questions aren't that bad. There's even architecture design questions (under System Design). Looks like a fun bedtime reading material to me. I'd say read this kind of stuff on regular days, not one night before interviewing, and peeps would do just fine.
michaelchisari 10y ago
Why do we test algorithms and not design patterns? It seems to me, after twenty years of building software, that the need for off-hand knowledge advanced algorithms is rare, and the need for knowledge of design patterns is exceedingly common.
jorgemf 10y ago
With this type of post I always read comments complaining why they should know those things for an interview. They are not necessary. It is like some more knowledge is going to harm them. I wish I would know more about everything. Sometimes the connection between knowledge and how to solve a problem are not clear when you learn that knowledge. Why is it important to know how is the syntactic structure of a sentence if I want to be a developer? Because you might end working with compilers or natural language processing and that knowledge is gold. But you simple don't know in advance, and you wont be able to discover how to solve a problem if you don't have knowledge about the solution in advance. And there are also different ways of solving problem, some better than other or with different trade offs which you only know if you are aware of other possible solutions.
- meheleventyone 10y ago
  I don't think most people are complaining about gaining knowledge but the relevance of the test to job performance or the requirement to study whilst working and raising a family. "... you wont be able to discover how to solve a problem if you don't have knowledge about the solution in advance." Is simply false, whilst research is a skill all of its own it's most definitely possible to go off and learn key techniques when you need too. Relying on serendipity for knowledge to be useful is not very efficient after all. At best the additional knowledge gained is a helpful side-effect.
  - jorgemf 10y ago
    It is not false, for example Albert Einstein was developing his Theory and he could do it because he was in a research ground where they were doing research about infinitesimal calculus, which was handy for Einstein to apply to his theory. But I think it wouldn't be clear to apply infinitesimal calculus to his theory if he didn't know it in advance. Or at least, we aware of it and its possibilities. When you face a new problem, you just don't know how to find a solution, you based your hypothesis in the knowledge you already have. You can do research, but the more knowledge you have the less research you will do. And that time you save is money the company saves. Anyway, you decide what to do with your life. If you are happier raising a family that is good. If you are happy learning stuff to apply to better jobs, that is good too. But obviously you cannot have everything because time is finite.
dragnot 10y ago
The problem is how much do dev really need to use this in real code. why would interviewer test someone on function he can just use existing lib for. why not think about how he plan an application and how will he design a flow. much more important.
throwawayhey 10y ago
Has anyone taken Outco or Interview Kickstart to pass these kind of questions? Which class is better?
Apocryphon 10y ago
Never mind the specifics of the selection process, Silicon Valley's risk-adverse approach to hiring is baffling. Instead of making candidates go through an overly rigorous process, why not embrace California's at-will status and hire and fire often? Employers and employees already view each other with suspicion in terms of loyalty, the former willing to downsize capriciously at any moment, and the latter willing to jump ship every year or two. So accept the mobility and instability of startups. Instead of spending immense resources on the interview process to find the perfect, you focus on getting the good and terminate swiftly if they turn out to be bad. Not to mention, even when you have these types of interviews it still doesn't seem to filter out toxic people, such as the harassers of Susan Fowler at Uber. Of course, it would be easier for workers to be okay with this arrangement if basic needs such as health insurance were decoupled from one's employer. That's another argument for single-payer in CA.
- ThrustVectoring 10y ago
  Good developers won't tolerate a contract-to-hire offer or will sniff out that they're a fire-fast environment. That, and it's pretty terrible for employee morale.
  - Apocryphon 10y ago
    I'm not suggesting contract-to-hire, so much as a formalized and transparent concept of probationary periods. I'm pretty sure at-will employment means you don't need to bother with contract-to-hire unless you want to be cheap with paying your employees benefits. So these employees shouldn't be on contract anyway unless expressly temporary. It certainly would be terrible for morale if implemented thoughtlessly. But if it was done in a way with clear expectations of employee performance, then terminations would not be arbitrary. And the morale hit of being terminated at any time- a situation with legally exists in California atm anyway- would be mitigated by more companies being quicker to hire instead of forcing long arduous interview processes. So then the situation becomes "If mgmt. is just, then they will keep me on, if they are dumb, then I can get quickly hired across the street anyway."
    - 10y ago
joelbondurant 10y ago
If mathematicians interviewed like computer scientists, timed arithmetic flash cards would be the skills benchmark.
mattfrommars 10y ago
Might be slight off topic. But I'm sort of Python enthusiast for a long time but never been able to actually learn how to code. I'm sort of aspiring software developer but a degree in irrelevant engineering. My question is, by studying/doing good amount of Python [currently working on it], going through the entire interview challenges presented here, seeking to gain Master degree in Management Information System [MIS], can I apply for job and be shortlisted which might require CS graduate and maybe graduate with MS in CS? Let's just say for the sake of the comment, I won't be able to obtain a MS in CS because for numerous reasons.
- xapata 10y ago
  Depends on whether it requires or "requires". There are all sorts of jobs out there. Read the curriculum of a CS degree. Compare the topics to the job requirements. Can you do the job?
- willchen 10y ago
  It's possible. I got a job as a software engineer at Google despite having a degree in Economics and only knowing Javascript. I spent a lot of time studying data structures & algorithms on my own but it's do-able.
tekkk 10y ago
To me it is reasonable to presume that a software developer candidate knows the basics of CS: algorithms, data structures and such but for anything that require deeper knowledge I think it should be only asked if it is mandatory for the job. Sure if you want to maintain a certain "prestige" you should maybe use them to limit your applicant pool but in the end if your work is nothing but coding front-end JavaScript it doesn’t matter do you know how to traverse B-trees or not. And if a need somehow arises it is very easily googleable and implementable with good enough CS education. I think what the interviews should be about, and the best that I have been, have involved some basics sure but also one had few “real-life” coding exercises and in another I had a code review about one of my project’s code (which I was surprised by). Nothing tells more about a person than having them to explain what is their passion but if you are only interested in people that can jump through some loops that’s the people you are going get. Maybe in that kind of company that's just how they do things. I’d argue most people can intuitively tell, maybe not why, when a recruitment process feels “right” compared to one that is forced and does nothing but dehumanize you to a walking Wikipedia and ticket-monkey. But maybe in programmers there is also some that seem to like that idea so I’d say it is more of a skill and culture fit than anything else. But in any case the whole process should be based on some structure that actually measures something real. I personally don’t like being reduced to few facts about missing knowledge on a spreadsheet which I could learn in a week or so. It hurts my ego and most of all makes not want to work in the said company in the future so when I’d know those things I won’t be reapplying.

451 points by sconxu 10y ago

v3gas 10y ago

Thanks!

The advent of all of these coding challenge excercises makes not being able to do one in an interview a real show stopper. Glad there's all this material to learn from.

JamesMcMinn 10y ago
Not really. If anything it just makes coding challenges useless for distinguishing between people who can think, and people who can regurgitate. It's one thing to "know" how to balance a binary tree because you've read up on and practiced the most common challenges - it's something else entirely to actually think through and understand a problem, then come up with a solution. I'd much rather have someone who can describe the edge cases and the complexity of a problem but get the final solution slightly wrong (but hey, the know the edge cases so can write tests for it, right?), than someone who can regurgitate code they've written before without really understanding it.
- gigatexal 10y ago
  Sure I agree as well. That there are so many resources and tools available to answer these coding challenges that if for whatever reason such a challenge was presented the minimum is to be able to answer thr challenge. Going beyond would be to know when to use such a data structure or its inherent strengths and weaknesses etc.
  - bigmanwalter 10y ago
    Unless someone can't study these things because they're too busy writing real-world code.
    - gigatexal 10y ago
      Which is why I think companies doing less whiteboard interviews and more real world coding tests make more sense. I think one could understand the limitations of a linked list and still use the built in data structures and be really competent.
- eriknstr 10y ago
  >It's one thing to "know" how to balance a binary tree because you've read up on and practiced the most common challenges - it's something else entirely to actually think through and understand a problem, then come up with a solution. There are too many things to know in the world in order to be able to know them all as deeply as we wish. For the things that we can get away with knowing the most common aspects of, time might be better spent elsewhere than to learn more about that thing.
bogomipz 10y ago
It's really amazing a whole industry has now sprouted up around hacking the interview process - you have interview boot camps, specific books about cracking the coding interview, mock interviews services with actual S.V engineers. As long as you have memorized how to reverse the last k elements of a doubly linked list you are probably a safe hire.

nickpeterson 10y ago

"Before we hire you, we first need you to outwit this burmese python..."

JamesMcMinn 10y ago
Honestly, I think you'd learn more about a potential hire that way than by presenting them with these sort of challenges.
- nickpeterson 10y ago
  "We see you're familiar with compression but how about pandas?"
  - dr_zoidberg 10y ago
    I fear the part of the interview that gets into spiders for web scraping...
riebschlager 10y ago
I'd rather take my chances with a snake than trying to solve "Add two integers without using + or -".
- brianwawok 10y ago
  sum([5,6]) ?
  - emidln 10y ago
    Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 2, in one_true_addition_test_case AssertionError The "correct" answer according to my pet parrot is (5).__add__(6). Of course, as per real-life, "correct" is usually just an aspect of if you find the interviewer's solution instead of whether your solution is actually correct. Better luck next time!
  - 10y ago

digitalsushi 10y ago

I'm a C+/B- developer. I've been doing this stuff for touching two decades, and these questions gave me a prickly sweat down my back. There is a part of me that feels very lucky to have plopped onto the Earth right when I did, before there was an organized process to weed me out. I'm entrenched enough that interviews are generally just culture fit interviews. I think I'd need ulcer medicine to get a job with no reputation.

JamesMcMinn 10y ago
How often have you had to code up solutions to any of these challenges in the last two decades? These sort of challenges are great for learning some of the theory behind computer science and getting you thinking, but they're not a useful part of the interview process imo.
- collyw 10y ago
  Exactly. I am pretty sure there is a (well tested) library out there to do those things.
  - canttestthis 10y ago
    At some jobs we make the libraries you use to solve those problems. These interview questions test very basic CS concepts and many of them are essentially just extremely watered down versions of real life problems. I can teach a dev how to Google for libraries, I can't teach him basic CS concepts. I would much rather hire for the latter. In fact this whole thread makes me uncomfortable. I wouldn't want to work with anyone who gets nervous when told to reverse a linked list.
    - collyw 10y ago
      Sure, but those jobs are few and far between. If you are indeed writing that sort of code, then it makes complete sense to test people on that, but the vast majority of jobs using this style of testing are not.

bigmanwalter 10y ago

I don't understand code challenges. Can you even program without Google and Stack Overflow anymore? And god-forbid being experienced in a dozen frameworks and libraries if it's not the exact combination the company uses.

problems 10y ago
Yes, you're expected to be able to write basic stuff like most of these challenges without Google or StackOverflow. There are some however here that you really shouldn't be, like remembering specific algorithms - if you're just memorizing 20 different sorting algorithm's exactly implementation, clearly that's not producing much if any value for you. If someone however was to give you this Algorithm section https://nbviewer.jupyter.org/github/donnemartin/interactive-coding-challenges/blob/master/sorting_searching/merge_sort/merge_sort_solution.ipynb#Algorithm https://nbviewer.jupyter.org/github/donnemartin/interactive-... and tell you to implement it, that would prove whether you had the skills needed to properly use Google and StackOverflow for anything but a direct copy+paste and could be a very good test for a programmer. Basic data structures, knowing when to apply them and how to solve fairly straightforward challenges like "does this string contain any duplicate characters" when you have full use of Python's builtin data structures are completely fair interview questions in my opinion. Just picking 1 or 2 of these questions that seems vaguely related to your work is enough, combined with asking some basic technical stuff like "What's the difference between a class and an object?" can weed out a shocking number of people, showing they don't even have conversationally useful knowledge about a topic.
- jacquesm 10y ago
  I've been coding for 4 decades. There are so many different standard libraries and function calls to remember that only the people that are one-trick ponies (one ecosystem, deep knowledge) are going to be able to do the majority of these without an outside reference. And those are exactly the people you would not want for a job because they would most likely not have the flexibility to shift away from that ecosystem if there was a need because it would take them forever to get up to speed. It's much better to know how to use outside references efficiently and to be able to 'swap stacks' in a couple of weeks than it is to be an expert in some language that could very well be obsolete, and that's assuming that there are many jobs left today where deep knowledge of only one ecosystem will get the job done. The time when you could spend 4 years learning a specific library and language and then make a career out of that is long long gone. What we have today is more akin to enormous libraries sitting on fairly rickety narrow foundations where - if you're lucky - the documentation of that library is relatively good, and the half-life of the whole thing is measured in months, a year at best. Today you work in Python, 3 months from now in Go and a another 6 months after that it will be JavaScript, typescript, clojurescript, coffeescript or <insert your flavor here>. So, you want to have your problem programmed in Assembler, C, C++, Python, PHP, BASIC (name your dialect), JavaScript, Erlang, Python or I don't care how many other languages that you care to name I'll accept the challenge. But I won't cut off my external memory bank in order to prove that that is something I can do. (Well, truth be told I probably can do it in a couple of the above but that's mostly because there was a time when the world moved slow enough that you could actually invest a couple of years, but these days it is much better to know how to leverage open source and google than it is to know the gritty little bits of whatever language is in flavor this week.) Of course, if you are looking for 'javascript programmers' it is fair to ask some questions about javascript. But in my experience it is a lot more efficient to search for programming talent and good debugging and writing skills irrespective of what language they are currently trained in. Languages are a means to an end, programming is the skill you want, not 'a particular language programmer'.

RodericDay 10y ago

This feels way over-engineered. I just want to click and jump into a challenge, Project Euler stye. Every single page is overflowing with "Table of Contents", screenshots, code snippets, etc.

TuringNYC 10y ago

From what hear about some startups, the challenges are for the general candidate pipelines the company wants to weed out w/o fearing legal repercussions. The inside-track, friends, and frat candidates often get to skip right through the process or have copies of the problems/answers from insiders. (Illusion of merit.)

tedmiston 10y ago
I think this view is a little bit cynical. Hiring your friends which usually happens in the early stages is often more about having worked with them before or having them come in based on a recommendation / knowing they're a culture fit ahead of time etc. It's a way for small startups to spend less time on hiring, and increase their chances of getting talent that they couldn't necessarily attract on the broader market in the early stages.
- TuringNYC 10y ago
  I appreciate the feedback and you raise good points. However, i'm curious what purpose many of these exams serve...some guesses: - Because it is actually a good predictor of job success (does anyone think this is the case for anything but a handful of job roles?) - To be adding a hurdle to target those who really want the job (downside: it also adds a hurdle to top-notch gainfully employed people who dont have time to study for such exams) - Another is they just need something to reduce an otherwise overqualified pool of already qualified candidates (fair point, but at the risk of losing out candidates from concern one above.) - Legal risk mitigation -- add a quantitative measure to show a facade of merit and process. TBH, I have never been on the hiring side at a small firm, so I don't know. But I have seen several things: 1. People recruiting me to Amazon and practically giving me the exam questions (I declined mostly due to location) Same thing at two other firms (perhaps to get referral bonuses?) 2. An H1B process that is by-the-book correct yet entirely against the spirit of the program. 3. Tons of interviews, screenings, etc at big firms just to justify an already-decided inside candidate. This I witnessed firsthand and makes me really upset because of all the candidate time they waste and the false hope they give to people who were never in the running to being with.
10y ago

sparkling 10y ago

Semi off-topic, but i am curious. How much of CS fundamentals do you expect a backend (or fullstack) developer to recite in an job interview? I did all CS theory stuff many years ago at university, but i could not pass a interview test full with these CS basics. Isn't it far more important to know how to design a modern, maintainable, scalable web application? Know how an when to cache stuff. How to design a API. How to integrate with third party APIs. How to setup logging. How to sanitize data and other common security problems. How to setup test/build/deploy structures. Et cetera, you get the point. If, while building a web application, i encounter a "big data"/"data processing" problem, i will find a appropriate solution using CS best practices. But hell, i would struggle to implement a simple array sorting algorithm under pressure.

thecardcheat 10y ago
What matters is how much the company you want to work for expects you to whiteboard or code to pass their screens. Big company? You almost certainly need to have your CS challenge question toolbox full. Smaller company? Many follow the big company interview methodology, but some don't, so more likely you can get away with not breaking the spine on your Cracking the Coding Interview.
brianwawok 10y ago
I think if you are fresh out of college, cute little algo challenges are OK.. because a) You should have just learned it b) You don't have years of experience with 12 languages Anything past fresh college grad and they are pretty dumb...
stuaxo 10y ago
As a fullstack developer most of these things are not needed. Having a good understanding of what is optimal is good, but you shouldn't have to be able to recite all the big O notation. Funnily enough none of the tests I've had ever talk about relevant things like data normalisation / de-normalisation or anything that will be used in the project.
- collyw 10y ago

southphillyman 10y ago

I really appreciate the effort that went in to this. This is a perhaps the most thorough hand holding through a "Cracking the Code Interview" regimen I've seen thus far.

iamspoilt 10y ago

Thank you for this! Cheers!

cauterized 10y ago

I see these challenges as a great way for excellent experienced developers to weed out incompetent companies. I'm a kick-ass get-things-done full-stack web engineer. I've never had to deal with one of these sorts of problems in my day to day work; and if I did, I'd just find an existing, tested, stable library that already handled them. A company that needs someone to solve these sorts of problems doesn't want me on their team in the first place, nor would I thrive there. A company that just needs to build damn good web apps is losing out by using these sorts of questions in their interviews. The best interview challenge I've had (actually, it was a take-home, with discussion in the interview proper) was about designing code for re-use and extension. It was a great indicator of the company's practical and mature approach to engineering, and of what they really wanted this hire to accomplish.

humanrebar 10y ago
I agree 95%. However, inevitably there will be a developer that will want to implement a trie for reasons. It's hard to be able to reason with her (or technical leadership when appealing the decision) when advocating for an off the shelf alternative if you can't explain why this isn't a brand new problem. On the flip side, one actually does need to create a new data structure on occasion, and obviously there we would want to be able to implement the common alternatives. Anyway, it's complicated. Especially when hiring for technical leadership.
- vonmoltke 10y ago
  If I need to convince another developer that a particular path is well-worn and that they are drifting towards NIH syndrome I have the benefit of time to develop an argument and resources with which to do so. I do not have 45 minutes, no resources, and just a whiteboard. To pre-counter an expected objection, if your company makes significant decisions like that in a single 45-minute (or any length, really) meeting you need to change your design process, not your hiring process.
  - humanrebar 10y ago
    > I have the benefit of time to develop an argument and resources with which to do so. One would assume so. That's not always the case in my experience. Improvisational discussion of design tradeoffs and costs happen a lot. YMMV, I guess. Though I agree that no-google, closed-book, no-IDE whiteboard development is very unnatural. > ...if your company makes significant decisions like that in a single 45-minute (or any length, really) meeting you need to change your design process, not your hiring process. I'd agree with that, but design processes on the whole tend to more dysfunctional than organizations realize. There's still a lot stuff running on deprecated OSs, dead languages, and mountains of technical debt.

throwaway2016a 10y ago

In a way I prefer this to "how many ping pong balls can fit in a school bus" that was all the rage in the 90s and early 2000s. But... man... I have a computer science degree, I've been coding for 20 years, and I've held (and kept) a CTO role at two mid-sized startup companies. Currently I'm considering looking for a job at a larger company (where I wouldn't be CTO but I'd be hopefully paid more) and these kind of questions make me think I need to almost go back to school before I can start interviewing. When did it get to the point where we need to read thick books on programming interviews and spend hundreds of hours on HackerRank practicing algorithms to get a job where we probably won't use any of those day-to-day? Edit: For fun the other day I decided to code a linked-list from scratch in C and it took me a half-hour plus... and I have known that data structure for decades. I can't imagine doing a harder problem under the pressure of being an interview.

sparkling 10y ago
I agree. To find out if one is actually competent, open questions that allow the candidate to elaborate on his previous problem solving experience are much more useful. Some examples: 1) Explain how and why you would implement authentication on a HTTP API. What other authentication methods do you know and why would you not use them? 2) Tell us about a scaling-up challenge/problem you had on your last application and how you solved it. 3) What technology stack would you use for a browser-based P2P file sharing application? 4) Name a library you recently discovered. What problem did it solve? 5) What mobile app on your phone right now has a bad user experience in your opinion? How would you make it better?
dahart 10y ago
Keep in mind that, because the number of programmers is increasing, the majority of them are fresh out of school or close to it. Algorithms interviews are largely designed for interviewing people who don't have much experience, so they're skewed toward testing what people learned in school. If after 2 CTO roles you interview for a job and they ask you to write a linked list algorithm, then would you want to work there? I mean you might, but that alone should at least beg the question. If they're not asking you how you'd manage a team of smart but stubborn coders or structure their company's software architecture and services to be more reliable, then they certainly aren't paying much attention to you or what your strengths and experience are. Or they simply don't know how to hire an experienced person, which signals that they don't know what to do with an experienced person once hired. Also, it would take the vast majority of great coders at least a half hour to code a linked-list from scratch in C and get it right, depending on what you're doing. So don't worry.

kclay 10y ago

I recently tried for the second time to apply to some agency type place. I have 10yrs of coding, worked with big data, have done micro coding( developed protocols for vending machine transactions), done frontend and backend small and large scale. But this place had 3 of these type of challenges that you had 1hr 30mins to complete all of them. I'm sorry, most of this stuff you will NOT find in any job unless its some specialty. For an backend/angular/react developer you will not find this at all. I feel that companies that do this are out of touch with the correct way to find candidates. But on the second hand I also see why they do this since programming has became so much popular now a days.

ethbro 10y ago
In the same way that nobody ever got fired for suggesting IBM, I imagine there's a lot of HR / tech hiring apeing MS/Google/FB. Even if it makes no sense in their business development context.

falcolas 10y ago

Somewhat of a tangent, but that "Distributed design" document gives me hives - with the lack of lines from "write" or "async write" back to the readers or cache. The taming of stale data would be a nightmare to manage when it suddenly starts to matter. Also, where's the completed response caching layer? Nothing destroys performance (and hikes costs) like having to recompute every page response from raw data. And that doesn't even touch my annoyance at shoehorning "federated architecture" to mean "sharding with a different algorithm".

swalsh 10y ago

This feels like hiring a new rough framer by asking him to carve a cabriole leg.

agentultra 10y ago

This is great! Having an integrated environment with the tests included and solutions in a separate notebook is quite valuable for training to pass technical interviews. I see a lot of people posting about how they dislike the technical interviewing process. The sentiment seems to be that for a certain class of popular developer role it's entirely unlikely that they will ever need to remember how to implement a heap or red-black tree to be effective at their job... so why use problems like this in an interview? I think these sorts of questions should be used by teams that want to set the minimum standards on the team. I'm reminded of a rule used at the Recurse Centre: never feign surprise when someone asks a question (I paraphrase). The idea is that if someone asks you a question about something you think is fundamental, like Bash for example, don't immediately feign surprise and say, "You don't know bash?" It's not helpful. Instead take it as an opportunity to teach them something awesome. However this doesn't generally work in a professional setting where you're required to know Bash in order to function at your job. If on my team we're responsible for the operation and maintenance of several millions of dollars worth of infrastructure that runs our customers' applications then there are certain minimum requirements for operating effectively within this team. I expect you would know Bash at a minimum. I should also expect you to know the network stack of the OS we deploy on, how TCP works, what a hypervisor is, etc. We may write most of our application code in a high-level language that abstracts these details away but that doesn't preclude you from understanding them. It's just a convenient tool. You have to know how to manage complexity and avoid premature pessimization in order to be effective and that means you will be interviewed using technical questions to screen for that minimum level of knowledge. However I think most companies do tend to use this tool poorly. I've interviewed with startups that build consumer web applications that ask questions about radix sort and k-d trees. That's what I call, overkill. This trap is easy to fall into if your motto is something glib and banal like, "We only hire the best." If you don't quantify what "best" is you're just going to negatively filter out potential candidates and hire on bias. You have to scale the screening process to only test for that minimum competency and choose how much risk you want to take in teaching new hires. If I'm hiring a more junior developer to our team I expect that we're going to mentor that person and make them a better engineer by working with us. They can ask questions that may be outside of our minimum standard. However if I'm hiring for a team-lead position I'm much more likely to not accept a candidate who cannot fly through our screening process. Working with them is going to be difficult and if it's 3 in the morning and they're causing more problems than fixing because they don't know how the TCP re-transmission protocol works then we're going to have a problem. The conclusion of all this is: tweak the screening process to set the minimum standards required for effective communication on the team. Don't set the bar unnecessarily high: define what the bar should be and assess the risk of mentoring junior developers. You need a good mix across the spectrum for an effective team.

dec0dedab0de 10y ago

looking at code that re-implements features of the language is annoying enough, but having it be so non-pythonic is just painful.

optimuspaul 10y ago

I have always seen the interview process as a an opportunity to understand how the other person thinks. These questions may do that to some extent but they limit it in ways that make it almost mechanical. I personally find "What is your favorite programming language?" or "What systems architecture to you find more compelling?" to be far more valuable. It gives some insight into their commitment to the trade and gives you an opportunity to make it a conversation to dive into their reasoning process and depth of knowledge about a topic. I think it's far easier to weed out the fakers if they can't express why Erlang is interesting to them than for them to tell you how to implement a linked list which is very easy to google and memorize(but won't necessarily prove any skill).

daenz 10y ago

Thanks for this. Just a mild constructive criticism: not sure how useful the Anki deck is. One thing to keep in mind when constructing cards is keeping the information very short. As it stands, there's no way to really remember the flip side of the card. Aside from that, really solid info!

prashnts 10y ago

I've been using Python (among others) at work close to 3 years now. I get these challenges and problems, however, I don't find the solutions here "pythonic". I guess it depends upon the job criteria, but the code here [1], for example, is not a great demonstration of _Python_ language skills. It is a good demonstration that the person knows Mathematics, but if someone is interviewing for a Python dev, it's not what they should be looking for. [1] https://nbviewer.jupyter.org/github/donnemartin/interactive-coding-challenges/blob/master/online_judges/license_key/format_license_key_solution.ipynb#Code https://nbviewer.jupyter.org/github/donnemartin/interactive-...

danielvinson 10y ago
That was my reaction also. If a junior engineer asked me to review that code, I would ask them to refactor in a way that is more maintainable.

didip 10y ago

These questions aren't that bad. There's even architecture design questions (under System Design). Looks like a fun bedtime reading material to me. I'd say read this kind of stuff on regular days, not one night before interviewing, and peeps would do just fine.

michaelchisari 10y ago

Why do we test algorithms and not design patterns? It seems to me, after twenty years of building software, that the need for off-hand knowledge advanced algorithms is rare, and the need for knowledge of design patterns is exceedingly common.

jorgemf 10y ago

With this type of post I always read comments complaining why they should know those things for an interview. They are not necessary. It is like some more knowledge is going to harm them. I wish I would know more about everything. Sometimes the connection between knowledge and how to solve a problem are not clear when you learn that knowledge. Why is it important to know how is the syntactic structure of a sentence if I want to be a developer? Because you might end working with compilers or natural language processing and that knowledge is gold. But you simple don't know in advance, and you wont be able to discover how to solve a problem if you don't have knowledge about the solution in advance. And there are also different ways of solving problem, some better than other or with different trade offs which you only know if you are aware of other possible solutions.

meheleventyone 10y ago
I don't think most people are complaining about gaining knowledge but the relevance of the test to job performance or the requirement to study whilst working and raising a family. "... you wont be able to discover how to solve a problem if you don't have knowledge about the solution in advance." Is simply false, whilst research is a skill all of its own it's most definitely possible to go off and learn key techniques when you need too. Relying on serendipity for knowledge to be useful is not very efficient after all. At best the additional knowledge gained is a helpful side-effect.
- jorgemf 10y ago
  It is not false, for example Albert Einstein was developing his Theory and he could do it because he was in a research ground where they were doing research about infinitesimal calculus, which was handy for Einstein to apply to his theory. But I think it wouldn't be clear to apply infinitesimal calculus to his theory if he didn't know it in advance. Or at least, we aware of it and its possibilities. When you face a new problem, you just don't know how to find a solution, you based your hypothesis in the knowledge you already have. You can do research, but the more knowledge you have the less research you will do. And that time you save is money the company saves. Anyway, you decide what to do with your life. If you are happier raising a family that is good. If you are happy learning stuff to apply to better jobs, that is good too. But obviously you cannot have everything because time is finite.

dragnot 10y ago

The problem is how much do dev really need to use this in real code. why would interviewer test someone on function he can just use existing lib for. why not think about how he plan an application and how will he design a flow. much more important.

throwawayhey 10y ago

Has anyone taken Outco or Interview Kickstart to pass these kind of questions? Which class is better?

Apocryphon 10y ago

Never mind the specifics of the selection process, Silicon Valley's risk-adverse approach to hiring is baffling. Instead of making candidates go through an overly rigorous process, why not embrace California's at-will status and hire and fire often? Employers and employees already view each other with suspicion in terms of loyalty, the former willing to downsize capriciously at any moment, and the latter willing to jump ship every year or two. So accept the mobility and instability of startups. Instead of spending immense resources on the interview process to find the perfect, you focus on getting the good and terminate swiftly if they turn out to be bad. Not to mention, even when you have these types of interviews it still doesn't seem to filter out toxic people, such as the harassers of Susan Fowler at Uber. Of course, it would be easier for workers to be okay with this arrangement if basic needs such as health insurance were decoupled from one's employer. That's another argument for single-payer in CA.

ThrustVectoring 10y ago
Good developers won't tolerate a contract-to-hire offer or will sniff out that they're a fire-fast environment. That, and it's pretty terrible for employee morale.
- Apocryphon 10y ago
  I'm not suggesting contract-to-hire, so much as a formalized and transparent concept of probationary periods. I'm pretty sure at-will employment means you don't need to bother with contract-to-hire unless you want to be cheap with paying your employees benefits. So these employees shouldn't be on contract anyway unless expressly temporary. It certainly would be terrible for morale if implemented thoughtlessly. But if it was done in a way with clear expectations of employee performance, then terminations would not be arbitrary. And the morale hit of being terminated at any time- a situation with legally exists in California atm anyway- would be mitigated by more companies being quicker to hire instead of forcing long arduous interview processes. So then the situation becomes "If mgmt. is just, then they will keep me on, if they are dumb, then I can get quickly hired across the street anyway."
  - 10y ago

joelbondurant 10y ago

If mathematicians interviewed like computer scientists, timed arithmetic flash cards would be the skills benchmark.

mattfrommars 10y ago

Might be slight off topic. But I'm sort of Python enthusiast for a long time but never been able to actually learn how to code. I'm sort of aspiring software developer but a degree in irrelevant engineering. My question is, by studying/doing good amount of Python [currently working on it], going through the entire interview challenges presented here, seeking to gain Master degree in Management Information System [MIS], can I apply for job and be shortlisted which might require CS graduate and maybe graduate with MS in CS? Let's just say for the sake of the comment, I won't be able to obtain a MS in CS because for numerous reasons.

xapata 10y ago
Depends on whether it requires or "requires". There are all sorts of jobs out there. Read the curriculum of a CS degree. Compare the topics to the job requirements. Can you do the job?
willchen 10y ago
It's possible. I got a job as a software engineer at Google despite having a degree in Economics and only knowing Javascript. I spent a lot of time studying data structures & algorithms on my own but it's do-able.

tekkk 10y ago

To me it is reasonable to presume that a software developer candidate knows the basics of CS: algorithms, data structures and such but for anything that require deeper knowledge I think it should be only asked if it is mandatory for the job. Sure if you want to maintain a certain "prestige" you should maybe use them to limit your applicant pool but in the end if your work is nothing but coding front-end JavaScript it doesn’t matter do you know how to traverse B-trees or not. And if a need somehow arises it is very easily googleable and implementable with good enough CS education. I think what the interviews should be about, and the best that I have been, have involved some basics sure but also one had few “real-life” coding exercises and in another I had a code review about one of my project’s code (which I was surprised by). Nothing tells more about a person than having them to explain what is their passion but if you are only interested in people that can jump through some loops that’s the people you are going get. Maybe in that kind of company that's just how they do things. I’d argue most people can intuitively tell, maybe not why, when a recruitment process feels “right” compared to one that is forced and does nothing but dehumanize you to a walking Wikipedia and ticket-monkey. But maybe in programmers there is also some that seem to like that idea so I’d say it is more of a skill and culture fit than anything else. But in any case the whole process should be based on some structure that actually measures something real. I personally don’t like being reduced to few facts about missing knowledge on a spreadsheet which I could learn in a week or so. It hurts my ego and most of all makes not want to work in the said company in the future so when I’d know those things I won’t be reapplying.