diegosouzapw Migration Planner Skill
Plan safe, zero-downtime migrations for schemas, services, and infrastructure.
Trigger Conditions
- Schema migration files are created or modified
- A service migration or infrastructure change is planned
- User invokes with "plan migration" or "migration strategy"
Input Contract
- Required: Current state (schema, service, infrastructure)
- Required: Target state (desired end state)
- Optional: Constraints (downtime window, data volume, timeline)
Output Contract
- Phased migration plan with rollback steps
- Risk assessment per phase
- Data validation checkpoints
- Estimated duration and resource requirements
Tool Permissions
- Read: Schema files, migration history, service configs
- Write: Migration plan documents, migration scripts
- Execute: Schema comparison tools
Execution Steps
- Analyze current and target state; identify delta
- Decompose into phases using expand-and-contract pattern
- Identify backward-compatibility requirements per phase
- Design rollback procedure for each phase
- Estimate data volume and migration duration
- Create validation checkpoints between phases
- Document the plan with risk scores
Success Criteria
- Every phase is independently rollback-able
- No phase requires downtime
- Data validation checkpoints defined between phases
- Risk assessment includes worst-case scenarios
Escalation Rules
- Escalate if migration affects >100M rows
- Escalate if cross-service coordination is required
- Escalate if estimated lock time exceeds 30 seconds
Example Invocations
Input: "Rename the users.email column to users.email_address"
Output: 3-phase plan: Phase 1 (add email_address column, backfill, dual-write), Phase 2 (switch readers to email_address, verify), Phase 3 (drop email column). Estimated: 2 deploys, 45min backfill on 5M rows. Rollback at each phase documented.