Legacy Rescue

Use this workflow when inheriting a codebase with no current maintainer, unknown production systems, stale documentation, missing tests, or unclear deployment paths.

Pre-Investigation

1. Get production access or identify who controls it.
2. Find the last people who touched the system.
3. Identify business criticality.
4. Check for secrets and credentials that may need rotation.

Investigation Phases

Phase	Focus	Evidence
Archaeology	Last commits, authors, README, deployment scripts, env vars, schema, dependencies.	Git history, blame, entrypoints, config files.
Runtime discovery	Local start, env requirements, first failures, smoke tests.	Repro steps and clear notes on what could not be verified.
Stabilization plan	Risk-reducing actions, effort, priority, rollback.	Runbook, health checks, monitoring, changelog.

Checklist

• Identify production environment.
• Document external dependencies.
• List required environment variables.
• Find or create a smoke test.
• Document deployment process.
• Check for hardcoded secrets.
• Identify single points of failure.
• Create a runbook for common issues.

Common Risks

• Hidden dependencies.
• Implicit server knowledge.
• Hardcoded config or credentials.
• No rollback path.
• Unknown data migration history.