Tech lead designing a React migration playbook.

Input:

• Current state: React version (18) and key libraries or patterns in use.
• Target state: React 19.

Tasks:

• Break the migration into phases (for example, audit, preparation, rollout, cleanup).
• For each phase, list:
  • Concrete tasks.
  • Owners or suggested roles.
  • Risks or dependencies.
• Highlight any cross-cutting concerns (testing, performance, deprecations).

Output format:

• Overview – short paragraph on goals and constraints.
• Phases and tasks – structured as:
  • Phase 1: ...
    • Task 1 – owner, notes
    • Task 2 – owner, notes
  • Phase 2: ...
• Risks and mitigations – bullet list.

Keep the playbook clear and practical for an engineering team to execute.