91–100 of 132 posts
I only have a few years of experience in this business, but I have seen numerous cases where none of this matters. Your perfectly drafted plan could easily be derailed by technical limitations, customer request or company reorg. You are better off use that planning time for something else.
These are some great tips! I have some notes: - One of the things about design you notice as you get older, is the bigger a software application is, the worse your options are later on. The design doc can be considered a proxy for the application: the bigger your design doc, the bigger the application will be. You should still try to think about as much of the app as you can in your design doc (don't intentionally tr…
I've never experienced a situation where a software design document meaningfully improved the overall process. At best, it helps to keep the business in sync at the expense of a much longer delivery timetable. Even high level software delivery contracts never seem to stay on rails for very long. It is often faster to just build the damn thing and see where it lands. Software is not like a nuclear power plant or offsh…
100%. I find it's generally used as a waterfall practice - i.e. BDUF first with a design document, then implement instead of "implement following conservative assumptions, revisit and refactor aggressively". The latter being vastly more effective at honing good design because more decisions are made in retrospect. I find that a spike or a spike PR to demonstrate a new approach (if a software design decision is contro…
Only if people actually do that.
I've joined a project where a design doc should've been written before the first line of code (as per the agreed upon dev process). Developers disregarded that and yolo'd their way to a first prototype. No documentation whatsoever. Then someone else was tasked with writing a design doc for that big ball of mud. You can imagine how that went.
I've joined the project only much later. At every corner I'm dumbfounded by the "design decisions". Refactoring now is a herculean task and kept to the minimum required.
I'm certainly not advocating for waterfall-like "make a plan and stick to it no matter the cost". But looking at the requirements and drafting a coarse design from those goes a long way. At least you can get idea if whatever you have though up is in agreement with the requirements.
Treat the design document as a living document. Do a coarse draft first. Implement. Refine the doc with stuff you've found out, ditch the stuff that didn't work. As a bonus you get a relatively neat on-boarding doc for people joining later.
Earlier quoted context omitted.
I think in the age of AI coding, these rationales are a bit outdated. And if you think they're not - I'm curious to know why you think so.
> I think in the age of AI coding, these rationales are a bit outdated. And if you think they're not - I'm curious to know why you think so. Can you share more about how you think AI invalidates these rationales?
For many systems, I'd argue technical documentation to understand how the internals are working can simply be handed off to the robots. Or generated on the fly. And if a requirement on the product level is not met, that can be changed under the hood.
As the other commenter said, "code is cheap" now.
Earlier quoted context omitted.
I'm looking for the places that need to be touched, but that wouldn't occur to me (and maybe not to an AI either) while I'm knee-deep in the code. Seeing where the AI touched isn't going to solve that.
If the feature works, and passes AI auditor agents with various hats (thinking of auth and security in particular), did that code you're not thinking of need to be touched? What effect did it have that cannot be captured in side effects, tests or audits?
Here's an example. You updated the code that interfaced with the database. But you forgot to update the stored procedures within the database. As a result, the database is now being put in an inconsistent state with every transaction that uses your new code. That is the kind of thing that a software design doc can help you remember, because it is supposed to make you think through all the stuff.
And if you're going to say "Your business stuff shouldn't be able to get into an inconsistent state", well, there's a lot of businesses that have potential landmines laying around. You can say they shouldn't. You're right, in an ideal world. But in this world, they do, and you have to live and work in the world that we have.
Now, in fairness, a good AI check might turn up that the database was left in an inconsistent state... if it understood the constraints well enough. If. I wouldn't want to gamble my production database on the AI's understanding and testing of all the constraints, though.
Earlier quoted context omitted.
The biggest thing AI enables is cheap code. That means you could choose to try three (or more) genuine implementations and explore their tradeoffs, instead of making three proposals in a document with one recommended (and the other two usually only provided for contrast). I do think the design is important to keep around - in particular, the constraints, the communication points, schema, tacit things that might not b…
> The biggest thing AI enables is cheap code. Agree, but in my experience that doesn't change much about the design doc. I think it's helpful to the author to be able to say to an AI agent, "Hey, put together this quick prototype," and that informs the design doc. But if the goal is to review the design decisions with the team, I don't see how you get around the design doc. I don't want a teammate to send me 10 KLOC…
I get the impression that Fable, when well directed, is better than maybe 80% of SWEs. Maybe more.
[edit: Yes, I'm maybe baiting other users, but I want to know your honest opinions on this.]
I've never experienced a situation where a software design document meaningfully improved the overall process. At best, it helps to keep the business in sync at the expense of a much longer delivery timetable. Even high level software delivery contracts never seem to stay on rails for very long. It is often faster to just build the damn thing and see where it lands. Software is not like a nuclear power plant or offsh…
100%. I find it's generally used as a waterfall practice - i.e. BDUF first with a design document, then implement instead of "implement following conservative assumptions, revisit and refactor aggressively". The latter being vastly more effective at honing good design because more decisions are made in retrospect. I find that a spike or a spike PR to demonstrate a new approach (if a software design decision is contro…
Throw the document away, it doesn't have any value.
But thinking through what you are going to do, in some detail, is valuable.
I blame the low cost of iteration in the software world (even lower now with LLMs).
Earlier quoted context omitted.
You have successfully optimized for fast, but you have not optimized for quality, extensibility, customer experience, or maintainability. Fast can be a great thing to optimize for, but there are many other situations where other optimizations are preferable.
Welcome both of you to the agile vs waterfall arguments of 25+ years ago. :) The agilists I think ended up having pretty good answers for finding a sweet spot between small iterations that maintained quality while minimizing Big Design Upfront to prevent spending a lot of time preplanning the software, allowing a well functioning agile team to maintain reasonably high quality, extensibility, maintainability and satis…