Deploy and roll back

Deploy (Vercel)

• Work on a branch; open a pull request.
• Test the Vercel preview URL.
• Merge to main to deploy to production.
• Run the app's health check.

Database changes (Supabase)

• Keep migrations in the repo.
• Apply to a development project first, then production.
• Take a backup before any destructive change.

Roll back

• Vercel: Deployments, pick the last good deployment, Promote to Production (or Instant Rollback).
• If a database migration was involved, restore from backup or apply a reverse migration. TODO: document tested procedure.
• Record the incident in the Decision log.

Railway (planned)

When adopted, document: which services move, deploy trigger, environment variables, and rollback method.