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Lesson 5: Your Team Needs Shared Rules

What are Constitutions?​

Constitutions are shared rules that apply to ALL specifications in your project.

Think of them as:

  • Quality standards
  • Organizational learning captured
  • Automatic guardrails

Example Constitution Rules​

Security​

  • All passwords must be hashed (bcrypt, cost 12)
  • All user input must be validated
  • No secrets in code or logs

Error Handling​

  • Return structured error objects (not strings)
  • Include error codes for client handling
  • Log errors with context

Performance​

  • API responses < 200ms (95th percentile)
  • Database queries must use indexes
  • Cache frequently accessed data

Bug → Rule Pattern​

When a bug is found:

  1. Fix the bug
  2. Add a Constitution rule to prevent it
  3. All future specs automatically check against it

Key Takeaway​

✅ Constitutions enforce quality at scale
✅ Organizational learning compounds over time
✅ Automatic checks prevent recurring mistakes

Continue to Lesson 6 →