Why Smart Engineers Fail at Requirements Despite Perfect Templates
Your requirements document is beautiful. Every edge case documented. Acceptance criteria crystal clear. User stories following perfect INVEST principles. You even got sign-off from three different stakeholders.
Then you ship it and realize you've broken checkout for enterprise customers because you didn't know about that weird middleware hook that's been there since 2019.
The problem isn't your template. The problem is you're writing requirements in a vacuum.
The Requirements Theater
I've watched this play out dozens of times. Smart engineer gets tasked with "adding OAuth support." They do everything right:
Three weeks into implementation, they discover the existing auth system has a custom session manager that conflicts with OAuth tokens. The user model doesn't support multiple auth providers. The API gateway caches credentials in a way that breaks token refresh.
None of this was in the requirements because none of this was knowable from a requirements document. You can't specify requirements for a system you don't understand.
Why Templates Can't Save You
Requirements templates exist because we want to believe software development is predictable. Fill out the form, check the boxes, ship the feature. It's comforting.
It's also fantasy.
The best requirements template in the world can't tell you:
What existing code will be affected by your change
Which team last touched that code (and if they still work here)
What other features depend on the thing you're about to modify
Why that weird conditional exists in the payment flow
What technical debt you're about to make worse
You know what's in your requirements doc? Hopes and assumptions.
Here's what actually happens: You write requirements based on how you think the system works. Then during implementation, you discover how it actually works. So you either hack around the mismatches (creating technical debt) or you go back and rewrite the requirements (which everyone interprets as "the engineer doesn't know what they're doing").
Both options suck.
The Codebase Knowledge Problem
The real issue is knowledge. Not process, not templates, not stakeholder alignment. Knowledge.
Most engineers know their slice of the codebase pretty well. Maybe you own the checkout flow and you understand every line. But the moment your requirements touch authentication, or inventory, or the email service, you're guessing.
You can't write good requirements when you're guessing.
I worked on a team that spent two weeks specifying a "simple" feature to let users edit their orders after checkout. The requirements looked great. Then we discovered:
Orders get replicated to three different systems
Inventory reservation happens asynchronously
The warehouse integration doesn't support modifications
Payment processing state is stored in two places that sometimes disagree
Customer service has a separate tool that will now show stale data
The requirements didn't mention any of this because nobody knew all of this. The engineer writing the spec knew the web UI. They had no idea about the warehouse system. Why would they?
When "Just Look at the Code" Doesn't Work
The obvious advice: "Just read the code before writing requirements."
Sure. Let me just read through 500,000 lines of code real quick. Maybe grep for some patterns. Follow some call chains.
By the time you've traced through enough code to write informed requirements, you've already wasted the time you were trying to save with requirements in the first place.
Plus, code reading doesn't tell you why things are the way they are. That conditional that seems weird? It's there because of a production incident in 2022 that nobody documented. Good luck finding that by reading code.
What Actually Works
The teams that write good requirements—the ones that actually match reality and don't need constant revision—have something in common: they have a clear map of what exists.
Not documentation that goes stale the moment it's written. Not Confluence pages that nobody updates. An actual, current understanding of what the system does and how it fits together.
When you know that the payment system has five different flows (not three, like the docs say), you write different requirements. When you can see that the customer model is used by twelve different services (not the four you thought), you think harder about your changes. When you understand that three other teams have features in flight that touch the same code, you coordinate differently.
This is where something like Glue becomes useful. It automatically indexes your entire codebase—not just the code, but the APIs, the database schema, the actual features that exist—and keeps that knowledge current. You're not reading stale docs or grepping through code. You're looking at a map of reality.
The Impact Analysis Gap
Here's a test: Before implementing your last feature, did you know every other piece of code that would be affected?
Be honest. Most of us don't. We know the obvious stuff. We might catch some edge cases during code review. But the full blast radius? The cascading effects? The features that will subtly break because they depended on behavior you're changing?
We find out in production.
Good requirements include impact analysis. "This change will affect X, Y, and Z. We need to update these five other features. These three teams need to coordinate."
But you can't write that without understanding the system. And understanding the system at that level is basically impossible manually once you're past the first 10,000 lines of code.
The Feature Documentation Problem
Most codebases are a graveyard of features. Half of them work. A quarter sort of work. The rest are in some quantum state between deployed and broken.
Your requirements need to account for existing features. Not the features you think exist based on that product roadmap from six months ago. The features that actually exist, actually work, and actually have users.
When you're adding "export to CSV," you need to know about the other four export features already in the codebase. Maybe one of them is deprecated but still getting traffic. Maybe another one has a performance problem you're about to replicate. Maybe there's a shared export service you should be using but nobody told you about.
This isn't in your requirements template because you don't know what you don't know.
Glue's automatic feature discovery helps here. It maps what features actually exist by analyzing code, APIs, and usage patterns. You're not relying on product docs or tribal knowledge. You're looking at what the system actually does.
Requirements That Match Reality
Stop treating requirements like they exist in a vacuum. They don't. Every requirement is really saying "change the system from state A to state B."
You need to know state A.
That means:
What code exists and what it does
How features actually work (not how they're supposed to work)
Who owns what and who knows what
What's changed recently and what's stable
What technical debt you're about to inherit
Your template can't capture this. Your two-week research phase can't capture this. It needs to be captured continuously, automatically, by something that actually understands code.
The best requirements I've seen aren't long documents. They're short documents written by people who deeply understand the existing system. They spend two paragraphs on user stories and eight paragraphs on "here's what already exists, here's what conflicts, here's what we need to coordinate."
That's the requirements document that actually helps.
Stop Playing Requirements Theater
You don't need a better template. You need better knowledge of your own codebase.
You don't need more stakeholder meetings. You need to know what will actually break when you ship.
You don't need a more rigorous process. You need to see the system as it actually is, not as you think it is.
Requirements fail because we're writing them blind. We're specifying changes to a system we don't fully understand, then acting surprised when reality doesn't match our specs.
The fix isn't better requirements. It's better understanding. Everything else is just theater.