We tend to think of code as the "real work" and documentation as the chore we do afterwards. This mindset is backward. Code tells the computer *what* to do. Documentation tells humans *why* it was done that way.
Without the "why," code becomes a black box. The engineer who wrote it leaves, and suddenly that module is "legacy code" that everyone is afraid to touch.
"Code is read ten times more often than it is written. Optimize for the reader, not the writer."
The "Bus Factor"
If the only person who understands your deployment pipeline got hit by a bus tomorrow (or, more likely, won the lottery), would your company survive?
Tribal knowledge—information stored only in people's heads—is a massive operational risk. Documentation democratizes this knowledge. It ensures that the project's IQ isn't tied to any single individual's employment status.
ADRs: Architectural Decision Records
One of the most valuable forms of documentation is the ADR. It's a simple log entry that answers:
- What decision was made?
- What alternatives were considered?
- Why did we choose this path?
Six months from now, when someone asks "Why are we using PostgreSQL instead of Mongo?", you can point to the ADR instead of trying to remember a Slack conversation from last year.
Self-Documenting Code is a Myth
"My code is self-documenting" is usually an excuse for laziness. Yes, variable names should be clear. But variable names can't explain *business logic*, edge cases, or the trade-offs you made to hit a deadline.
Write comments that explain the *intent*, not the syntax.