The Founding Engineer's Guide to Handing Off Frontend Architecture
You built it all yourself. Here's how to make it survive without you.
You wrote the first line of code. You chose React, set up the repo, picked the state management approach, and built the first 40 screens. You know where everything lives because you put it there. Now you're hiring engineers 3 and 4, and they're asking questions you've never had to answer.
Your codebase has a bus factor of one. If you get sick, the frontend stalls.
The Four Pillars of Handoff
1. Architecture Decision Records (ADRs)
Short documents capturing why you made specific technical decisions. Not how — why.
Write ADRs for every non-obvious decision: state management, folder structure, API layer, authentication, testing, styling. You should have 8-15 ADRs. It takes an afternoon and saves weeks of "why did we do it this way?" conversations.
2. Conventions Document
ADRs explain why. Conventions explain how. Cover: file/folder conventions, component patterns, state management rules, API integration pattern, error handling.
3. Reference Implementations
Pick 2-3 screens that represent the "right way" and mark them explicitly. When a new developer asks "how should I build this?", the answer is "look at the Analytics Dashboard."
4. Automated Guardrails
Every convention should have a corresponding lint rule, type check, or CI validation. When I set up automated guardrails for a client, code review comments dropped by about 60%.
The Handoff Timeline
Week 1: Audit and document. Write ADRs, create conventions doc, identify reference implementations.
Week 2: Automate. ESLint rules, pre-commit hooks, CI checks.
Week 3: Test the documentation. Have the next hire build a feature using only the docs. Watch where they get stuck — those are gaps in documentation, not ability.
Week 4: Iterate. Fix the gaps. This is a living process.
Common Mistakes
Over-documenting. A 50-page guide nobody reads is worse than a 3-page one everyone follows.
Documenting the current mess. Pick the right pattern, document it, create tickets to migrate the others.
Not letting go. Accept that other engineers will make different decisions. If conventions are clear and guardrails are in place, let the team own it.
A codebase that only its creator understands is a liability. The fix is a focused two-week investment that pays dividends for years.