Deployment Gotchas

Use this skill before modifying ANY deployment or release configuration.

Canonical FP bar: docs/fcis-engineering-rules.md — Functional Core, Imperative Shell: pure domain modules; side effects at edges. Workers and pipelines are edges: fetch IDs, call pure core, return tagged tuples.

RULES — Follow these with no exceptions

1. Use runtime.exs for all secrets and URLs; never hardcode secrets — use System.get_env!/1 — see §1 & §5 2. Run migrations via release commands (bin/migrate) — see §2 3. Set PHX_HOST and PHX_SERVER=true — see §3 4. Run mix assets.deploy before building the release — see §4 5. Add a /health endpoint that queries the database — see §6 6. Use config :logger, level: :info in production — see §7 7. Use Docker multi-stage builds for Elixir releases — see §4

End-to-End Deployment Workflow