fullstack-validation

Use whenever validating a multi-layer app where frontend depends on backend depends on database — Rails+React, Django+Vue, Next.js+Postgres, any monorepo or separate repos that share data. Runs a strict bottom-up protocol: verify DB schema and seed data first, then API CRUD, then frontend rendering, then cross-layer integration flows (create in frontend → appears in DB, insert in DB → appears in frontend, update via API → propagates everywhere, delete cascades). Reach for this when a bug could be in any layer and you need to prove which one, or before shipping a change that touches more than one layer.