Why I document design decisions

I used to treat documentation as something you do after the design is finished — a chore you rush through before handoff. The work looked done, so I wrote a few lines explaining the layout and moved on. That habit broke the first time I came back to one of my own files a few months later and couldn't remember why I had chosen one pattern over another.

The decision is the design

A screen is just pixels. The actual design is the reasoning behind it: why this flow and not that one, which constraint forced a compromise, what I considered and rejected. When I write that down, two things happen. First, my thinking gets sharper — vague reasoning doesn't survive being written in plain sentences. Second, the decision becomes reusable. The next time I face a similar problem, I have a record of what I tried and why.

This matters even more on concept projects. When there are no real users or stakeholders to anchor decisions, it's tempting to just make something that looks good. Writing the rationale forces me to answer the harder questions: who is this for, what problem does it solve, why does this detail exist? If I can't answer, the detail probably shouldn't exist.

Handoff is a design artifact too

A handoff that only says what was built leaves the developer guessing at why. Why is this spacing 24px and not 16? Why does this empty state have a button and that one doesn't? Every unanswered "why" becomes a guess, and guesses drift. I've started treating the decision log as part of the deliverable — short, plain-language notes next to the flows, not a formal document nobody opens.

For my future self

The person who benefits most is me, six months from now, looking at a file I barely remember making. A decision I wrote down takes thirty seconds to re-read; a decision I didn't takes hours to reconstruct. This blog is partly that: a public version of the notes I was already writing for myself, cleaned up enough that they might be useful to someone else too.