Verification Gates

You are implementing verification gates - explicit checkpoints where work is validated before proceeding. This prevents cascading errors and ensures quality at each phase.

Core Principle

Never proceed to the next phase with unverified assumptions from the previous phase.

A verification gate is a deliberate pause to confirm that prerequisites are met before continuing.

Why Verification Gates Matter

Without gates:

Phase 1 → Phase 2 → Phase 3 → Phase 4
   ↑
   └── Error discovered at Phase 4
       Must redo Phases 2, 3, 4

With gates:

Phase 1 → [Gate] → Phase 2 → [Gate] → Phase 3 → [Gate] → Phase 4
             ↑
             └── Error caught immediately
                 Only redo Phase 1

Standard Verification Gates

Gate 1: Requirements Verification

Before starting design:

• All requirements are documented and clear
• Ambiguities have been resolved with stakeholders
• Non-requirements are explicitly stated
• Acceptance criteria are defined
• Edge cases are identified

Actions:

1. Review requirements document
2. Identify any unclear items
3. Get explicit confirmation on ambiguous points
4. Document answers

Gate 2: Design Verification

Before starting implementation:

• Design addresses all requirements
• Technical approach is validated
• Interfaces are defined
• Data model is complete
• Error handling is planned
• Design has been reviewed (self or peer)

Actions:

1. Walk through design against requirements
2. Review with rubber duck or teammate
3. Check for missing pieces
4. Get approval to proceed

Gate 3: Implementation Verification

Before calling task complete:

• Code compiles/runs without errors
• All tests pass
• New code has test coverage
• Code follows project conventions
• No obvious bugs or issues
• Dependencies are appropriate

Actions:

1. Run full test suite
2. Self-review the diff
3. Check for code smells
4. Verify against acceptance criteria

Gate 4: Integration Verification

Before merging:

• Feature works end-to-end
• Integration tests pass
• No regression in existing functionality
• Performance is acceptable
• Documentation is updated

Actions:

1. Test the full user flow
2. Run integration test suite
3. Compare performance metrics
4. Review documentation changes

Gate 5: Deployment Verification

Before marking complete:

• Feature works in target environment
• Monitoring shows no errors
• Feature flags are properly configured
• Rollback plan exists
• Stakeholders can verify

Actions:

1. Smoke test in environment
2. Check error logs and metrics
3. Get stakeholder sign-off
4. Document deployment

Gate Types

Automated Gates

Gates that can be enforced automatically:

# CI Pipeline Gates
gates:
  - name: lint
    command: npm run lint
    required: true

  - name: type-check
    command: npm run typecheck
    required: true

  - name: unit-tests
    command: npm test
    required: true
    coverage: 80%

  - name: build
    command: npm run build
    required: true

Manual Gates

Gates requiring human judgment:

## Manual Verification Checklist

Before Code Review:
- [ ] I've tested my changes locally
- [ ] I've written/updated tests
- [ ] I've read my own diff
- [ ] I've checked for security issues
- [ ] I've updated documentation

Before Deployment:
- [ ] Code review approved
- [ ] QA verified (if applicable)
- [ ] Stakeholder approved (if required)
- [ ] Deployment plan reviewed

Conditional Gates

Gates that apply in specific situations:

Condition	Required Gates
Security-related	Security review
Public API change	API review + migration plan
Database change	DBA review + backup plan
Performance-sensitive	Performance test
Breaking change	Deprecation notice + migration

Implementing Gates

In Your Workflow

Task Start
    │
    ▼
┌─────────────────┐
│ Gate: Prereqs   │ ← Verify before starting
│ - Requirements  │
│ - Dependencies  │
└────────┬────────┘
         │
         ▼
    Do the work
         │
         ▼
┌─────────────────┐
│ Gate: Completion│ ← Verify before proceeding
│ - Tests pass    │
│ - Code reviewed │
└────────┬────────┘
         │
         ▼
Task Complete

Gate Documentation Template

## Gate: [Name]

**When:** [Before what action]

**Purpose:** [What this gate ensures]

**Checklist:**
- [ ] Item 1
- [ ] Item 2
- [ ] Item 3

**Verification Method:**
- [How to verify each item]

**Failure Actions:**
- [What to do if gate fails]

**Approver:** [Who can approve passage]

Common Gate Failures

"Just this once" Syndrome

• Problem: Skipping gates for urgent work
• Fix: Urgent work gets simpler gates, not no gates

Gate Inflation

• Problem: Too many gates slow everything down
• Fix: Only gates that catch real issues

Rubber Stamp Gates

• Problem: Gates passed without real verification
• Fix: Specific checklists, evidence requirements

Gate Metrics

Track gate effectiveness:

Gate Effectiveness = Issues caught at gate / Total issues
Gate Overhead = Time spent at gates / Total development time
Gate Value = (Cost of issue caught early) / (Gate overhead cost)

Good gates have:

• High effectiveness (catch most issues)
• Low overhead (quick to pass)
• High value (prevent expensive fixes)

Integration with CI/CD

# GitHub Actions example
jobs:
  gate-lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm ci
      - run: npm run lint

  gate-test:
    needs: gate-lint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm ci
      - run: npm test

  gate-build:
    needs: gate-test
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm ci
      - run: npm run build

  deploy:
    needs: gate-build
    # Only deploys if all gates pass

Quick Reference

Phase	Gate Before	Key Checks
Design	Requirements	Clear, complete, approved
Implementation	Design	Reviewed, feasible
Review	Implementation	Tests, conventions, working
Merge	Review	Approved, conflicts resolved
Deploy	Merge	Environment ready, plan exists

Integration with Other Skills

• design-first: Gates validate design before implementation
• task-decomposition: Gates between task phases
• testing/red-green-refactor: Tests are key gate criteria
• collaboration/structured-review: Review is a gate