4 ms·
> genuinely had tough problems where if they accidentally did something in O(N^2), their half-day compute job would suddenly literally take centuries to complet
by p4wnc6 11y ago
> genuinely had tough problems where if they accidentally did something in O(N^2), their half-day compute job would suddenly literally take centuries to complete.
Yes, but this has almost zero bearing on the actual interview. Being able to avoid this in real life means that you measure twice and cut once, you pay attention, and you ask for help and training. Being able to do something similar with dynamic programming or tree riddles in an interview has absolutely nothing to do with those longer-view skills.
> Google really needs most of their engineers that will naturally spot this kind of thing in code reviews, because if every engineer on the indexing team made a mistake like that once a year, the indexing system would always run at half speed, sometimes even 1/3 or 1/4 speed.
Again, this has nothing to do with puzzle interviews. In this case, you could hire smart people almost independently of whether they had encountered certain data structures before, and certainly without much concern about how fast they could spot things like this in an interview setting. And instead, hire for general aptitude, and then invest in training someone to be able to spot these things to the necessary degree.
Even though you can provide impressive-seeming examples of problems where minor tweaks in complexity or subtle implementation-specific points about data structures can result in huge problems, it's still not supportive of whiteboard-hazing style interviews that test more for interview aptitude than anything else.
After all, whoever it was that wrote the ML regex job, that person passed the interviews (and that person may have rightfully passed the interviews and deserved to work for Google, even after this later evidence that they weren't careful enough in one case).
- rhizome 11y agoI think what the GP was illustrating is that Google is extremely conservative. For them to hire people outside of the strict boundaries of, "dimensions of skills as represented in an interview," is kind of a rejection of the Robustness Principle for corporate purposes. I mean, heck, something like this? They interview multiple magnitudes of people necessary for this kind of job. I respect it as a hedge, but it probably also takes people out of the industry who could do more vital work someplace else.
- p4wnc6 11y agoEven so, it only pays to be conservative via an overly selective filter if that filter actually selects for what you want. If you zealously apply some filter, believing that you're being extra cautious, but the filter doesn't actually select for what you think, or the filter isn't actually as selective as you think, then it's just a form of selectivity theater. I've met plenty of ex-Googlers who were great at reciting CS trivia, but actually not very good at real life engineering. Granted, that may be why they were ex-Googlers, but it still doesn't speak well of Google's hiring process.
- rhizome 11y agoI don't doubt it. They've got a (evolving) process that has a lot of false negatives. The creativity vaunted by the earlier poster is more common in the rejects, and as a long-time Android (and Google) user I can draw a correlation. And none of this counters that Google's hiring process has been engineered to produce a conservative model of acceptible employee.
- p4wnc6 11y agoI'm saying it produces false positives. False negatives are ok for a conservative hiring process, because you're paying for a super low false positive rate with a higher budget for false negatives. But the whiteboard hazing produces too high a rate of false positives -- candidates who can recite CS trivia, study in a way tailored and overfitted to the interviews, and then pass them and be hired even if they don't actually have the broader skills that the interview was designed to conservatively filter for. I speculate that new hires at Google aren't much better at anything than new hires anywhere else. They might become better later due to a compounding returns effect of already being at Google, but the hiring process didn't select them because they already were better. Instead, the hiring process is a status show, selectivity theater, to enhance the promotional reputation of a business-conquering nerds stereotype and to enhance Google's bargaining power by convincing people that they are only worthwhile to the extent they jump through interview hoops.
- 11y ago