Impact Analysis

Find the blast radius before writing code, not after the deploy. Output is a short report the dev (and the reviewer) can trust.

Step 1: Pin down what's changing

Get the concrete list of things being changed: model names, field names, endpoint paths, serializer fields, function or task names, settings, env vars. Read them from the ticket/PRD, or ask the dev. Vague input ("the billing stuff") gives a vague report, so push for names.

Step 2: Find all the repos

Read the repo map (../repo-map.md or docs/repo-map.md). It lists sibling repos and who consumes what. If there's no map, list the sibling folders of the current repo and treat every git repo there as in scope, then suggest running repo-map afterwards.

Step 3: Trace

Search every repo, not just the current one. For each changed thing, look for: