8 ms·

Why Write ADRs

207 points by imsky 6y ago

cosmic_quanta 6y ago
I had never heard of ADRs, but now I see that I've been putting some of the information in comments or module-level docs. I'll definitely look into the linked examples!
- Inversechi 6y ago
  A community that I've seen doing this pretty well is the Home Assistant community. You might wanna check their examples out. https://github.com/home-assistant/architecture https://github.com/home-assistant/architecture
rabidrat 6y ago
These articles about engineering process always put the responsibility solely in the implementing engineer's lap. Always more and more work to achieve JPL-level capability maturity, no matter your budget or headcount. Of course we want unit tests for every case, and verbose explanation in every atomic commit message, and architecture documents that are seldom read before they become stale. But make sure you also get your story points done for this sprint and meet your OKRs for this quarter.
- aplummer 6y ago
  > But make sure you also get your story points done for this sprint and meet your OKRs for this quarter. The problem here is the points aren't measuring quality, they are measuring a type of velocity that doesn't take into account quality if you aren't getting points for that work. Read: PMs often drive a timeline that accepts engineering risk, but not responsibility for that decision when it doesn't work.
  - deleted 6y ago
    [deleted]
  - dfcowell 6y ago
    This is fundamentally missing the point about what story points are, and goes to show you’re unfortunately stuck in another of the many companies using them poorly. Many (poor) product managers look at velocity dropping and blame the team, or try to pack sprints. In fact, this is the time to open dialogue with the team and get to the bottom of why. Often, it’s because tech debt or poor architecture is making it difficult to implement even simple features. The team might be burning out. There might be an overwhelming number of bugs and support tickets that need to be addressed. Story points aren’t a target to hit, or even a KPI. They’re a barometer for team and process health. Unfortunately most engineering and product managers either don’t get it, or are unable to appropriately communicate that fact upwards.
- DyslexicAtheist 6y ago
  what you mention are real pain points, though from my experience they actually were a lot simpler than locking info away in some external tool. there is very little additional cognitive cost with adr's and from what I've experienced they add other value too such as a record of why things were done which saves a lot of time when you're ramping up and onboarding new team members who have a tendency to discuss why things are done in a specific way and not another. when used correctly they're not just another thing to take care of but an actual time saver (have personally avoided many meetings by simply pointing new people to them - and they have the benefit of structuring and capturing the architecture discussions in a central place right next to your code ... (if the git log history isn't enough for us we use gitlab comments on changes the same way we would use it on code). it's brilliant because it's so simple imo.
- dllthomas 6y ago
  I've been intrigued by ADRs for a bit, and this post prompted me to start a conversation with my current team. Quoting something I posted in my internal slack: > Note that my goal, with ADRs, is not to increase the amount of time we spend on decisions! If the answers are "I didn't think too deeply and I'm going with my gut" it's still better to have that documented. If we find that we're getting bit by bad decisions, we can look at how those decisions were made and how we can improve them at that point, with much more context.
- dgb23 6y ago
  I can only directly relate to solo/small-team projects: I find writing text (preference: Markdown) and sprinkling it with visualizations (tables, graphviz...) to document stuff very useful and productive. I don't see this as a burden but rather the opposite. A good portion of programming is not writing code, but thinking and communication. Using text as a direct output of this process helps in many areas. Mostly because we have a limited capability of keeping stuff in our heads at any given time. A typical categorization of these documents would be: - specification: describing the thing you build in detail - todo-lists: organizing actions - guides/instruction: describing usage of the thing you build in a accessible manner - meeting & discussion protocols The thing is: None of these things are extra or can be avoided. The only difference is whether you write them down or not. The article describes something I would put into the fourth category, or maybe a fifth where you describe intent historically (like design documents). I personally don't write design-documents or ADRs, nor have I ever seen them. But I assume that these become valuable in larger organizations and teams with a higher communication overhead. As soon you need to talk about these things over and over you want to write these down.
  - rabidrat 6y ago
    > As soon you need to talk about these things over and over you want to write these down. This is the relevant part, to me. Can we do this documentation process JIT when someone asks about it? Maybe even convert the dialogue (in chat) or transcript of the conversation into the documentation.
    - dgb23 6y ago
      I just started to write anything down basically... When a collaborator or client talks to me or when I think about something, then I open a markdown file (first often just a notes.md) and just write in bullet points, and gradually organize it into categories. I put these in version control as well since a while. Thought experiment: if something is not worth writing down, is it worth discussing?
      - rmdashrfstar 6y ago
BillSaysThis 6y ago
Shout out to my pal Joel, who was in this space for awhile already! https://github.com/joelparkerhenderson/architecture_decision_record https://github.com/joelparkerhenderson/architecture_decision...
linux2647 6y ago
I started a new job about six months ago and the engineering org writes ADRs. As a new hire, this was incredibly useful to understand some of the hows and whys of past decisions that would normally take me years to discover or understand.
- dglass 6y ago
  I started a new job about two months ago and completely agree. The ADRs and Feature Specs have been immensely helpful in getting context around why certain decisions were made and the tradeoffs considered when making decisions. It's especially useful because I joined the team during Covid and haven't actually met anyone else in person yet. I can't just turn around in my chair and ask someone at the desk next to me why something is the way it is. Now it involves pinging someone, setting up a zoom call, etc.
  - zimpenfish 6y ago
    I joined a place recently and there was zero documentation, zero ADRs, zero discussions logged except vaguely in Slack, etc. Consequently I was completely baffled about why everything was as it is for the first few months ("Where do I find a network?" "It's in the frobnob_stash table under 'lemon'." "Oh, yeah, OBVIOUSLY.")
iainmerrick 6y ago
The basic idea is good, but isn’t a commit message the best place for this? That will ensure that people will find it when looking through source control history to understand some code, but equally importantly, they won’t find it on its own and be unsure whether it’s still relevant. When it’s part of the git history, the history itself tells you whether those changes stuck around or were superseded. Checking the original post to make sure I’m not just repeating it, I don’t think I am -- it links to https://github.com/joelparkerhenderson/architecture_decision_record https://github.com/joelparkerhenderson/architecture_decision... which proposes a whole bunch of acronyms (ADL, ADR, AKS, ASR) but doesn’t offer an opinion on where they should be stored! This is bureaucracy for bureaucracy’s sake, missing the wood for the trees. Edit to add: I’m not quite right, it does offer an opinion; it suggests text files in an “adr” directory. For the reasons outlined above I think this is both more and less than you need. (Maybe there should be an ADR for the location of the ADR directory...?) TL;DR: we don’t need a whole new set of complex workflows for this, we just need good commit messages.
- ralphael 6y ago
  so what would the experience be for someone new joining the project, particular if you have many repositories? having to search across numerous repositories? In practice I've found this (source control commit messages as ADR's) doesn't work. Unless I have mistaken what you have said? I just keep a repository for ADR's, which can then be published to a wiki or else where.
  - iainmerrick 6y ago
    In that situation, I think the best layout is: - your centralised wiki lists all the repositories and explains what they’re for; - each repository has a detailed commit history, allowing you to understand the thinking behind each line of code. Edit to add: you can search across multiple repos with Github’s “search in organization” feature, and it actually works very well. I usually find that much more useful than searching through a wiki that’s separate from the code (although maybe I just haven’t ever seen a wiki that was sufficiently well organized?)
sbuttgereit 6y ago
This is far from the first time I've evangelized this paper here on HN... but I think the ideas of the OP and the Naur paper "Programming as Theory Building" have a high degree of overlap. Indeed, at some level, the Naur paper deals with identifying the problem while the OP deals with practices to bridge the knowledge gap identified in the paper. http://pages.cs.wisc.edu/~remzi/Naur.pdf http://pages.cs.wisc.edu/~remzi/Naur.pdf
- jonnydubowsky 6y ago
  Thanks for the recommendation! Already enjoying this!
  - usrme 6y ago
    There are also plain text versions of that paper if you're interested: - https://pastebin.com/raw/WwXKAGnW https://pastebin.com/raw/WwXKAGnW - https://gist.github.com/onlurking/fc5c81d18cfce9ff81bc968a7f342fb1 https://gist.github.com/onlurking/fc5c81d18cfce9ff81bc968a7f...
jayd16 6y ago
So this is somewhere between code comments and Confluence pages. Seeing as even comments can get stale, how accurate do these docs stay? The added focus on "why" instead of "what" seems more resistant to cruft.
- qznc 6y ago
  They are not supposed to be updated. It captures a decision at one point in time with lots of context. If an update is necessary, you create a new ADR.
- coldtea 6y ago
  >Seeing as even comments can get stale, how accurate do these docs stay? Part of the idea is that they're immutable, append-only. They express why an architecture / decision was made, when it was made.
  - dllthomas 6y ago
    Not that it takes anything away from your point, but to be slightly more precise, the content should (probably, see below) be treated as immutable. The metadata, included in the same files, is mutable - things like status, related ADRs, superseding PRS, etc. Above I said probably - I'm not sure that we shouldn't allow editing when it's purely clarification, communicating more clearly what it already communicated to most of the audience. An append-only section for adding further observations, as the decision plays itself out, is also an interesting option, although I don't know whether it would actually be more valuable than distracting.
- ajsharma 6y ago
  Yes, I think of them as blogs. New engineers can read along and see the evolution of thoughts and design decisions.
- dllthomas 6y ago
  If comments on the same line (or an adjacent line, such that it shows up in `git diff` output and the default code review display) get stale then that is a pretty bad failure of both the programmer and the reviewer(s); in my experience that doesn't happen very often. A much bigger issue is comments that are a few lines (or a few tens of lines) away from some piece of what they're talking about. Then, they suffer from exactly the same issue as documentation anywhere, inside the repo or out: something drew the developers attention to the code that needed to be changed, but then there was no reason they should have known to look in this particular other location for text talking about what they changed. That's not the programmer's fault, unless we want our programmers to take the time to review every piece of documentation for anything that might need to be changed. I'd guess there are some contexts where that's appropriate, but I haven't ever worked in one. Alternatively, we could have it be someone's job to own the docs, continually run over them and make sure they still apply, and stay abreast of PRs as they merge. I haven't seen that tried - it might be valuable if it was a role someone wanted. What I've been trying is adding cross-references to my code, so that something can always be visible on the line or a neighboring line that notes that there's something relevant in another place. This is then checked in CI for integrity, and references that appear in the diff have their referents surfaced on the PR for the benefit of the reviewer. So far the links are pretty sparse, but have already been somewhat valuable. I intend to piggyback on the same system as I introduce ADRs. I'd like to release the above tooling as F/OSS but really the trickiest parts are CI integration. The check is literally piping git diff to grep, looking for things of the form ^^{some label} and finding the associated @@{some label}. I decorate the PR on github with annotations through the Git Checks API.
alsdkfjkqjwer 6y ago
yet another name for documentation nobody will write, but the manager will be able to say "solved the lack of documentation this quarter by implementing XYZ".
deleted 6y ago
[deleted]
wdb 6y ago
They could have included some nice examples from GitHub themselves in this blog article.
- usrme 6y ago
  Wholly agree with you. That's what I'm always hoping for when big company X does a blog post about thing Y, that they actually show some examples about how they have implemented thing Y as otherwise the post falls a bit flat (for me).
euske 6y ago
I think the fundamental idea behind this is that "every decision must be rationalized", which is fine, but in reality it's difficult to pull off in my opinion. Because people (including myself) are so easily fooled, I'm afraid that it's often the case that we deliberately ignore certain (inconvenient) facts or unconsciously distort things. If we are really trying to rationalize ourselves, the decisions have to be reviewed by multiple people.
- qznc 6y ago
  I would agree that ADRs are not really necessary if you work alone. Maybe not even within a team if it stable over a long time. Where ADRs are helpful is when many teams cooperate and if people come and go. The reviews happen implicitly because the decision is discussed among many people.
  - janee 6y ago
    I'm not sure. I work in a small stable team and I had to do a tech due diligence report... it's really amazing being able to go two years into the past and pull the exact reasons why certain design decisions were made. Not all our designs and decisions panned out ofc, but just having the articles already helped a ton getting through that DD and it really helps give new starts a much better feeling for the code base and where it came from
- dasil003 6y ago
  Not sure about that. Writing software requires heavy rationalization just to get a minimally working system. This is one reason some people aren't cut out to be programmers—they just don't have to patience to deal with the pedantic requirements of implementing cold, hard, unambiguous system logic. I think it's more about documentation of that rationalization, and I wouldn't want to raise the bar on this by requiring a review. The value of every engineer just braindumping the roughest cut of their thinking already provides a tremendous amount of value over the history of a long-lived code base. Personally I do this in commit messages even for solo projects, but for larger teams/code bases/SOAs a more formal document-based approach allowing for diagrams and additional metadata is highly valuable if done consistently.
Pxtl 6y ago
I think whether you use adrs or comments or git messages or readmes or whatever, the fundamental rule is simple: In any case where you're making a non-default choice in software, it needs to be explained in an easily-discoverable place so a developer that's looking at the project and trying to understand the why of something can see it. Too often I block PRs with confusing code and ask why it was done this way and the developer swings by my office or gets defensive and I have to say "no, I'm not attacking your code as being wrong, and I don't want a verbal explanation as to how it works. I want the decisions that led you to do it this way to be documented". ... But actually usually the code is just wrong.
arcticbull 6y ago
I'm personally a huge fan of the SPADE framework from Gokul Rajaram. First Round has a really good write-up on how to use it. [1] It serves both as an ADR and also a framework for making that decision in the first place, in one. I've introduced this at a few places I've worked and it's been very well received. [1] https://firstround.com/review/square-defangs-difficult-decisions-with-this-system-heres-how/ https://firstround.com/review/square-defangs-difficult-decis...
- dangoor 6y ago
  At Khan Academy, we've been using ADRs for three years now, using Michael Nygard's format as a starting point. We adopted ADRs at the same time we adopted DACI (Driver, Approver, Contributors, Informed) as a decision making framework across the organization, so our ADRs server both of these purposes as well.
jsdalton 6y ago
The “whys” here all sound sensible, but I’d be even more interested in _how_ people are implementing a process around ADRs, where you’re keeping them, etc. At work we have a decent PR template that prompts people to provide context, alternatives considered, and underlying reasons for the change, which works pretty well. I’m trying about how or whether ADRs would function better, or if they would operate at a slightly higher level of change (i.e. for work that extends across multiple PRs). I’d be interested in thoughts or experience people have, especially in medium or larger organizations.
- qznc 6y ago
  I'm the software architect in a automotive project with ten teams. We use Confluence to write ADRs. We only use this process for changes which affect multiple teams. Pro: Wysiwyg is great for editing it live in meetings, plugins like Gliffy are nice for diagrams, integration with Jira, accessible with a simple link. Con: Not good enough for long term archival, so we export them to pdf regularly, wiki has no atomic commits. We have a regular meeting where the team architects together discuss and ultimately approve these documents.
- rham 6y ago
  I recently rolled off a sweet FinTech project with a Fortune 500 bank’s Emerging Technologies team which has the best ADR implementation I’ve seen thus far. Just fyi, these ADRs, written in Markdown, are kept in separate repo with special Markdownlint rules applied to ensure consistent formatting. But what made this team’s ADR implementation stand out to me were not the technical details of how they were maintained, but rather the SOPs they’d strictly adhered to. In essence, they had a very academic perspective on ADRs, viewing them more like a potentially publishable white-paper- not necessarily in terms of length or formality, but procedurally. The rule we followed was that a spike should lead to an ADR, which made writing an ADR much more of a build-measure-learn cycle and kept quality high, since authors weren’t scrambling to remember their entire thought process after the fact. This also greatly improved the quality of the spikes themselves, as we spent less time falling down rabbit holes. Basically, a spike became strictly a determination of either feasibility or implementation, with an explicit record of that the determination and the way in which it was made, as well as the other trade-offs considered.
vemv 6y ago
Quite ironically (given it's Github who are defending ADRs in the article), I avoid ADRs by using Github more richly: before working on a branch at all I create a substantial issue (think: multiple paragraphs, links to related issues/PRs, etc) and try to ping the team for feedback. The design process will ideally happen asynchronously, as comments posted in the issue. That way, a truthful trail of diverse considerations will be left in written form. Contrariwise, ADRs can be too written excessively after-the-fact, by a single person. I have seen them degenerate into bureaucracy ("we designed X because X seemed the best option"... how informative).
- zimpenfish 6y ago
  > That way, a truthful trail of diverse considerations will be left in written form. But isn't that just an organic ADR?
- dllthomas 6y ago
  > "we designed X because X seemed the best option"... how informative If that's the most they can say, I'd rather that be surfaced. Knowing the decision was made in haste, with shallow consideration, is better than wondering if it was. And actually, that's probably the right way to make some decisions, if they seem likely to have a small difference in value between the many options it doesn't make a lot of sense to burn too many cycles making sure of that. Once decisions come around to bite you, you can start to look at whether the decisions that are actually proving costly were the ones that were made lightly. At least, that's how I'm thinking about it before getting into the weeds of it.
arthurcolle 6y ago
Thought this was going to be about American Depositary Receipts. Was disappointed... :(
timwis 6y ago
I’m hoping to implement this in my organisation very soon. There are still a couple things I need to figure out: 1. How do I articulate the criteria for when a decision should have an ADR? 2. I always see ADRs in the context of recording what was decided, but I’d like them to be raised more like requests for comments (RFCs) for a week or two first, particularly in cases where there may be impacts on other systems, security or data protection implications. Are ADRs often used this way, or should I be looking at something else? Any advice?
- willejs 6y ago
  1. I usually advise people to raise an ADR when they are adding new component to a system, a new technology, or really anything that they feel needs context and want to have a discussion about. Usually I advise either making a pr in the repo for that component (this can be in #1 with the first commits of code) or in a centralised docs repo when you are adding new technologies to your stack or setting standards etc. 2. I have used them in place of RFCs at a couple of places. Generally I would write code or docs alongside an ADR and use the comments in a pull request to get a review on it, and try to improve the PR with the comments. If there is a consensus in the PR from enough people it would get merged in, if not i would take it to an appropriate forum to discuss it (guild, standup, meeting etc). I have found creating a couple of ADRs in a team and getting that team to participate in the process first is a great example to showcase to an organisation at a show and tell, lunch and learn etc. Adr-tools is a great tool to help create an ADR and provides a good template too!
draven 6y ago
We use Kanban in my organisation and tickets go through a Analysis phase where the dev spells out the technical details of what they're going to do and then an Analysis review where two other devs will validate the analysis. Then the ticket can move to the implementation phase itself. It may seem a lot of overhead at first but the team is small and tickets go through these two phases fast. The analysis can be considered sort of an ad-hoc ADR. We started this quite recently but it's already useful and did not slow us down.
- dllthomas 6y ago
  It's related, but I think it's not quite the same thing. It sounds like you are describing the intended design of the feature you're implementing. As I understand it, an ADR may also set policy regarding future features, where they touch an architectural concern.
brainzap 6y ago
When Should I Write an Architecture Decision Record https://engineering.atspotify.com/2020/04/14/when-should-i-write-an-architecture-decision-record/ https://engineering.atspotify.com/2020/04/14/when-should-i-w...

207 points by imsky 6y ago

I had never heard of ADRs, but now I see that I've been putting some of the information in comments or module-level docs. I'll definitely look into the linked examples!

Inversechi 6y ago
A community that I've seen doing this pretty well is the Home Assistant community. You might wanna check their examples out. https://github.com/home-assistant/architecture https://github.com/home-assistant/architecture

rabidrat 6y ago

These articles about engineering process always put the responsibility solely in the implementing engineer's lap. Always more and more work to achieve JPL-level capability maturity, no matter your budget or headcount. Of course we want unit tests for every case, and verbose explanation in every atomic commit message, and architecture documents that are seldom read before they become stale. But make sure you also get your story points done for this sprint and meet your OKRs for this quarter.

aplummer 6y ago
> But make sure you also get your story points done for this sprint and meet your OKRs for this quarter. The problem here is the points aren't measuring quality, they are measuring a type of velocity that doesn't take into account quality if you aren't getting points for that work. Read: PMs often drive a timeline that accepts engineering risk, but not responsibility for that decision when it doesn't work.
- deleted 6y ago
  [deleted]
- dfcowell 6y ago
  This is fundamentally missing the point about what story points are, and goes to show you’re unfortunately stuck in another of the many companies using them poorly. Many (poor) product managers look at velocity dropping and blame the team, or try to pack sprints. In fact, this is the time to open dialogue with the team and get to the bottom of why. Often, it’s because tech debt or poor architecture is making it difficult to implement even simple features. The team might be burning out. There might be an overwhelming number of bugs and support tickets that need to be addressed. Story points aren’t a target to hit, or even a KPI. They’re a barometer for team and process health. Unfortunately most engineering and product managers either don’t get it, or are unable to appropriately communicate that fact upwards.
DyslexicAtheist 6y ago
what you mention are real pain points, though from my experience they actually were a lot simpler than locking info away in some external tool. there is very little additional cognitive cost with adr's and from what I've experienced they add other value too such as a record of why things were done which saves a lot of time when you're ramping up and onboarding new team members who have a tendency to discuss why things are done in a specific way and not another. when used correctly they're not just another thing to take care of but an actual time saver (have personally avoided many meetings by simply pointing new people to them - and they have the benefit of structuring and capturing the architecture discussions in a central place right next to your code ... (if the git log history isn't enough for us we use gitlab comments on changes the same way we would use it on code). it's brilliant because it's so simple imo.
dllthomas 6y ago
I've been intrigued by ADRs for a bit, and this post prompted me to start a conversation with my current team. Quoting something I posted in my internal slack: > Note that my goal, with ADRs, is not to increase the amount of time we spend on decisions! If the answers are "I didn't think too deeply and I'm going with my gut" it's still better to have that documented. If we find that we're getting bit by bad decisions, we can look at how those decisions were made and how we can improve them at that point, with much more context.
dgb23 6y ago
I can only directly relate to solo/small-team projects: I find writing text (preference: Markdown) and sprinkling it with visualizations (tables, graphviz...) to document stuff very useful and productive. I don't see this as a burden but rather the opposite. A good portion of programming is not writing code, but thinking and communication. Using text as a direct output of this process helps in many areas. Mostly because we have a limited capability of keeping stuff in our heads at any given time. A typical categorization of these documents would be: - specification: describing the thing you build in detail - todo-lists: organizing actions - guides/instruction: describing usage of the thing you build in a accessible manner - meeting & discussion protocols The thing is: None of these things are extra or can be avoided. The only difference is whether you write them down or not. The article describes something I would put into the fourth category, or maybe a fifth where you describe intent historically (like design documents). I personally don't write design-documents or ADRs, nor have I ever seen them. But I assume that these become valuable in larger organizations and teams with a higher communication overhead. As soon you need to talk about these things over and over you want to write these down.
- rabidrat 6y ago
  > As soon you need to talk about these things over and over you want to write these down. This is the relevant part, to me. Can we do this documentation process JIT when someone asks about it? Maybe even convert the dialogue (in chat) or transcript of the conversation into the documentation.
  - dgb23 6y ago
    I just started to write anything down basically... When a collaborator or client talks to me or when I think about something, then I open a markdown file (first often just a notes.md) and just write in bullet points, and gradually organize it into categories. I put these in version control as well since a while. Thought experiment: if something is not worth writing down, is it worth discussing?
    - rmdashrfstar 6y ago

BillSaysThis 6y ago

Shout out to my pal Joel, who was in this space for awhile already! https://github.com/joelparkerhenderson/architecture_decision_record https://github.com/joelparkerhenderson/architecture_decision...

linux2647 6y ago

I started a new job about six months ago and the engineering org writes ADRs. As a new hire, this was incredibly useful to understand some of the hows and whys of past decisions that would normally take me years to discover or understand.

dglass 6y ago
I started a new job about two months ago and completely agree. The ADRs and Feature Specs have been immensely helpful in getting context around why certain decisions were made and the tradeoffs considered when making decisions. It's especially useful because I joined the team during Covid and haven't actually met anyone else in person yet. I can't just turn around in my chair and ask someone at the desk next to me why something is the way it is. Now it involves pinging someone, setting up a zoom call, etc.
- zimpenfish 6y ago
  I joined a place recently and there was zero documentation, zero ADRs, zero discussions logged except vaguely in Slack, etc. Consequently I was completely baffled about why everything was as it is for the first few months ("Where do I find a network?" "It's in the frobnob_stash table under 'lemon'." "Oh, yeah, OBVIOUSLY.")

iainmerrick 6y ago

The basic idea is good, but isn’t a commit message the best place for this? That will ensure that people will find it when looking through source control history to understand some code, but equally importantly, they won’t find it on its own and be unsure whether it’s still relevant. When it’s part of the git history, the history itself tells you whether those changes stuck around or were superseded. Checking the original post to make sure I’m not just repeating it, I don’t think I am -- it links to https://github.com/joelparkerhenderson/architecture_decision_record https://github.com/joelparkerhenderson/architecture_decision... which proposes a whole bunch of acronyms (ADL, ADR, AKS, ASR) but doesn’t offer an opinion on where they should be stored! This is bureaucracy for bureaucracy’s sake, missing the wood for the trees. Edit to add: I’m not quite right, it does offer an opinion; it suggests text files in an “adr” directory. For the reasons outlined above I think this is both more and less than you need. (Maybe there should be an ADR for the location of the ADR directory...?) TL;DR: we don’t need a whole new set of complex workflows for this, we just need good commit messages.

ralphael 6y ago
so what would the experience be for someone new joining the project, particular if you have many repositories? having to search across numerous repositories? In practice I've found this (source control commit messages as ADR's) doesn't work. Unless I have mistaken what you have said? I just keep a repository for ADR's, which can then be published to a wiki or else where.
- iainmerrick 6y ago
  In that situation, I think the best layout is: - your centralised wiki lists all the repositories and explains what they’re for; - each repository has a detailed commit history, allowing you to understand the thinking behind each line of code. Edit to add: you can search across multiple repos with Github’s “search in organization” feature, and it actually works very well. I usually find that much more useful than searching through a wiki that’s separate from the code (although maybe I just haven’t ever seen a wiki that was sufficiently well organized?)

sbuttgereit 6y ago

This is far from the first time I've evangelized this paper here on HN... but I think the ideas of the OP and the Naur paper "Programming as Theory Building" have a high degree of overlap. Indeed, at some level, the Naur paper deals with identifying the problem while the OP deals with practices to bridge the knowledge gap identified in the paper. http://pages.cs.wisc.edu/~remzi/Naur.pdf http://pages.cs.wisc.edu/~remzi/Naur.pdf

jonnydubowsky 6y ago
Thanks for the recommendation! Already enjoying this!
- usrme 6y ago
  There are also plain text versions of that paper if you're interested: - https://pastebin.com/raw/WwXKAGnW https://pastebin.com/raw/WwXKAGnW - https://gist.github.com/onlurking/fc5c81d18cfce9ff81bc968a7f342fb1 https://gist.github.com/onlurking/fc5c81d18cfce9ff81bc968a7f...

jayd16 6y ago

So this is somewhere between code comments and Confluence pages. Seeing as even comments can get stale, how accurate do these docs stay? The added focus on "why" instead of "what" seems more resistant to cruft.

qznc 6y ago
They are not supposed to be updated. It captures a decision at one point in time with lots of context. If an update is necessary, you create a new ADR.
coldtea 6y ago
>Seeing as even comments can get stale, how accurate do these docs stay? Part of the idea is that they're immutable, append-only. They express why an architecture / decision was made, when it was made.
- dllthomas 6y ago
  Not that it takes anything away from your point, but to be slightly more precise, the content should (probably, see below) be treated as immutable. The metadata, included in the same files, is mutable - things like status, related ADRs, superseding PRS, etc. Above I said probably - I'm not sure that we shouldn't allow editing when it's purely clarification, communicating more clearly what it already communicated to most of the audience. An append-only section for adding further observations, as the decision plays itself out, is also an interesting option, although I don't know whether it would actually be more valuable than distracting.
ajsharma 6y ago
Yes, I think of them as blogs. New engineers can read along and see the evolution of thoughts and design decisions.
dllthomas 6y ago
If comments on the same line (or an adjacent line, such that it shows up in `git diff` output and the default code review display) get stale then that is a pretty bad failure of both the programmer and the reviewer(s); in my experience that doesn't happen very often. A much bigger issue is comments that are a few lines (or a few tens of lines) away from some piece of what they're talking about. Then, they suffer from exactly the same issue as documentation anywhere, inside the repo or out: something drew the developers attention to the code that needed to be changed, but then there was no reason they should have known to look in this particular other location for text talking about what they changed. That's not the programmer's fault, unless we want our programmers to take the time to review every piece of documentation for anything that might need to be changed. I'd guess there are some contexts where that's appropriate, but I haven't ever worked in one. Alternatively, we could have it be someone's job to own the docs, continually run over them and make sure they still apply, and stay abreast of PRs as they merge. I haven't seen that tried - it might be valuable if it was a role someone wanted. What I've been trying is adding cross-references to my code, so that something can always be visible on the line or a neighboring line that notes that there's something relevant in another place. This is then checked in CI for integrity, and references that appear in the diff have their referents surfaced on the PR for the benefit of the reviewer. So far the links are pretty sparse, but have already been somewhat valuable. I intend to piggyback on the same system as I introduce ADRs. I'd like to release the above tooling as F/OSS but really the trickiest parts are CI integration. The check is literally piping git diff to grep, looking for things of the form ^^{some label} and finding the associated @@{some label}. I decorate the PR on github with annotations through the Git Checks API.

alsdkfjkqjwer 6y ago

yet another name for documentation nobody will write, but the manager will be able to say "solved the lack of documentation this quarter by implementing XYZ".

deleted 6y ago

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wdb 6y ago

They could have included some nice examples from GitHub themselves in this blog article.

usrme 6y ago
Wholly agree with you. That's what I'm always hoping for when big company X does a blog post about thing Y, that they actually show some examples about how they have implemented thing Y as otherwise the post falls a bit flat (for me).

euske 6y ago

I think the fundamental idea behind this is that "every decision must be rationalized", which is fine, but in reality it's difficult to pull off in my opinion. Because people (including myself) are so easily fooled, I'm afraid that it's often the case that we deliberately ignore certain (inconvenient) facts or unconsciously distort things. If we are really trying to rationalize ourselves, the decisions have to be reviewed by multiple people.

qznc 6y ago
I would agree that ADRs are not really necessary if you work alone. Maybe not even within a team if it stable over a long time. Where ADRs are helpful is when many teams cooperate and if people come and go. The reviews happen implicitly because the decision is discussed among many people.
- janee 6y ago
  I'm not sure. I work in a small stable team and I had to do a tech due diligence report... it's really amazing being able to go two years into the past and pull the exact reasons why certain design decisions were made. Not all our designs and decisions panned out ofc, but just having the articles already helped a ton getting through that DD and it really helps give new starts a much better feeling for the code base and where it came from
dasil003 6y ago
Not sure about that. Writing software requires heavy rationalization just to get a minimally working system. This is one reason some people aren't cut out to be programmers—they just don't have to patience to deal with the pedantic requirements of implementing cold, hard, unambiguous system logic. I think it's more about documentation of that rationalization, and I wouldn't want to raise the bar on this by requiring a review. The value of every engineer just braindumping the roughest cut of their thinking already provides a tremendous amount of value over the history of a long-lived code base. Personally I do this in commit messages even for solo projects, but for larger teams/code bases/SOAs a more formal document-based approach allowing for diagrams and additional metadata is highly valuable if done consistently.

Pxtl 6y ago

I think whether you use adrs or comments or git messages or readmes or whatever, the fundamental rule is simple: In any case where you're making a non-default choice in software, it needs to be explained in an easily-discoverable place so a developer that's looking at the project and trying to understand the why of something can see it. Too often I block PRs with confusing code and ask why it was done this way and the developer swings by my office or gets defensive and I have to say "no, I'm not attacking your code as being wrong, and I don't want a verbal explanation as to how it works. I want the decisions that led you to do it this way to be documented". ... But actually usually the code is just wrong.

arcticbull 6y ago

I'm personally a huge fan of the SPADE framework from Gokul Rajaram. First Round has a really good write-up on how to use it. [1] It serves both as an ADR and also a framework for making that decision in the first place, in one. I've introduced this at a few places I've worked and it's been very well received. [1] https://firstround.com/review/square-defangs-difficult-decisions-with-this-system-heres-how/ https://firstround.com/review/square-defangs-difficult-decis...

dangoor 6y ago
At Khan Academy, we've been using ADRs for three years now, using Michael Nygard's format as a starting point. We adopted ADRs at the same time we adopted DACI (Driver, Approver, Contributors, Informed) as a decision making framework across the organization, so our ADRs server both of these purposes as well.

jsdalton 6y ago

The “whys” here all sound sensible, but I’d be even more interested in _how_ people are implementing a process around ADRs, where you’re keeping them, etc. At work we have a decent PR template that prompts people to provide context, alternatives considered, and underlying reasons for the change, which works pretty well. I’m trying about how or whether ADRs would function better, or if they would operate at a slightly higher level of change (i.e. for work that extends across multiple PRs). I’d be interested in thoughts or experience people have, especially in medium or larger organizations.

qznc 6y ago
I'm the software architect in a automotive project with ten teams. We use Confluence to write ADRs. We only use this process for changes which affect multiple teams. Pro: Wysiwyg is great for editing it live in meetings, plugins like Gliffy are nice for diagrams, integration with Jira, accessible with a simple link. Con: Not good enough for long term archival, so we export them to pdf regularly, wiki has no atomic commits. We have a regular meeting where the team architects together discuss and ultimately approve these documents.
rham 6y ago
I recently rolled off a sweet FinTech project with a Fortune 500 bank’s Emerging Technologies team which has the best ADR implementation I’ve seen thus far. Just fyi, these ADRs, written in Markdown, are kept in separate repo with special Markdownlint rules applied to ensure consistent formatting. But what made this team’s ADR implementation stand out to me were not the technical details of how they were maintained, but rather the SOPs they’d strictly adhered to. In essence, they had a very academic perspective on ADRs, viewing them more like a potentially publishable white-paper- not necessarily in terms of length or formality, but procedurally. The rule we followed was that a spike should lead to an ADR, which made writing an ADR much more of a build-measure-learn cycle and kept quality high, since authors weren’t scrambling to remember their entire thought process after the fact. This also greatly improved the quality of the spikes themselves, as we spent less time falling down rabbit holes. Basically, a spike became strictly a determination of either feasibility or implementation, with an explicit record of that the determination and the way in which it was made, as well as the other trade-offs considered.

vemv 6y ago

Quite ironically (given it's Github who are defending ADRs in the article), I avoid ADRs by using Github more richly: before working on a branch at all I create a substantial issue (think: multiple paragraphs, links to related issues/PRs, etc) and try to ping the team for feedback. The design process will ideally happen asynchronously, as comments posted in the issue. That way, a truthful trail of diverse considerations will be left in written form. Contrariwise, ADRs can be too written excessively after-the-fact, by a single person. I have seen them degenerate into bureaucracy ("we designed X because X seemed the best option"... how informative).

zimpenfish 6y ago
> That way, a truthful trail of diverse considerations will be left in written form. But isn't that just an organic ADR?
dllthomas 6y ago
> "we designed X because X seemed the best option"... how informative If that's the most they can say, I'd rather that be surfaced. Knowing the decision was made in haste, with shallow consideration, is better than wondering if it was. And actually, that's probably the right way to make some decisions, if they seem likely to have a small difference in value between the many options it doesn't make a lot of sense to burn too many cycles making sure of that. Once decisions come around to bite you, you can start to look at whether the decisions that are actually proving costly were the ones that were made lightly. At least, that's how I'm thinking about it before getting into the weeds of it.

arthurcolle 6y ago

Thought this was going to be about American Depositary Receipts. Was disappointed... :(

timwis 6y ago

I’m hoping to implement this in my organisation very soon. There are still a couple things I need to figure out: 1. How do I articulate the criteria for when a decision should have an ADR? 2. I always see ADRs in the context of recording what was decided, but I’d like them to be raised more like requests for comments (RFCs) for a week or two first, particularly in cases where there may be impacts on other systems, security or data protection implications. Are ADRs often used this way, or should I be looking at something else? Any advice?

willejs 6y ago
1. I usually advise people to raise an ADR when they are adding new component to a system, a new technology, or really anything that they feel needs context and want to have a discussion about. Usually I advise either making a pr in the repo for that component (this can be in #1 with the first commits of code) or in a centralised docs repo when you are adding new technologies to your stack or setting standards etc. 2. I have used them in place of RFCs at a couple of places. Generally I would write code or docs alongside an ADR and use the comments in a pull request to get a review on it, and try to improve the PR with the comments. If there is a consensus in the PR from enough people it would get merged in, if not i would take it to an appropriate forum to discuss it (guild, standup, meeting etc). I have found creating a couple of ADRs in a team and getting that team to participate in the process first is a great example to showcase to an organisation at a show and tell, lunch and learn etc. Adr-tools is a great tool to help create an ADR and provides a good template too!

draven 6y ago

We use Kanban in my organisation and tickets go through a Analysis phase where the dev spells out the technical details of what they're going to do and then an Analysis review where two other devs will validate the analysis. Then the ticket can move to the implementation phase itself. It may seem a lot of overhead at first but the team is small and tickets go through these two phases fast. The analysis can be considered sort of an ad-hoc ADR. We started this quite recently but it's already useful and did not slow us down.

dllthomas 6y ago
It's related, but I think it's not quite the same thing. It sounds like you are describing the intended design of the feature you're implementing. As I understand it, an ADR may also set policy regarding future features, where they touch an architectural concern.

brainzap 6y ago

When Should I Write an Architecture Decision Record https://engineering.atspotify.com/2020/04/14/when-should-i-write-an-architecture-decision-record/ https://engineering.atspotify.com/2020/04/14/when-should-i-w...