dsivov/task-decomposition

Task Decomposition Expertise

When This Applies

Apply this guidance when:

• Breaking a CR into implementation tasks
• Creating technical sub-tasks from architecture
• Writing acceptance criteria for tasks
• Mapping task dependencies
• Estimating effort and sizing

Decomposition Process

Step 1: Identify Work Streams

From the CR and architecture, identify:

1. Data layer tasks — Models, migrations, storage
2. Logic layer tasks — Business logic, services, validation
3. Interface layer tasks — APIs, UI, integrations
4. Test tasks — Unit tests, e2e tests, test data
5. Infrastructure tasks — Config, deployment, CI/CD

Step 2: Size Each Task

A good task is:

• Completable in one session — If it takes more, break it down further
• Independently testable — Can be verified without other tasks
• Clearly scoped — Developer knows exactly what files to touch
• Has clear done criteria — Unambiguous definition of complete

Size Guidelines

| Size | Lines of Code | Files | Complexity | |------|--------------|-------|------------| | Small | < 50 | 1-2 | Straightforward | | Medium | 50-200 | 2-5 | Some decisions required | | Large | 200+ | 5+ | Break down further |

Step 3: Define Dependencies

Map which tasks must complete before others can start:

TASK-001 (data model) ─┬─▶ TASK-003 (API endpoint)
TASK-002 (auth logic)  ─┘         │
                                  ▼
                          TASK-004 (integration tests)

Mark dependent tasks in their descriptions. Assign upstream tasks first.

Step 4: Write Acceptance Criteria

Each task needs:

1. Given — Starting conditions and context
2. When — The action or change being made
3. Then — Expected outcome, verifiable result

Example:

Given: User model exists with email field
When: Login endpoint receives valid credentials
Then: Returns JWT token with 24h expiry and user profile

Task Assignment Guidelines

| Task Type | Assign To | |-----------|-----------| | Feature implementation | Developer | | Unit/e2e tests | Integrator | | API design review | Self (Architect) | | Database migrations | Developer (implement) → Integrator (commit) | | CI/CD changes | DevOp | | Deployment | DevOp → Production Engineer |

Common Decomposition Patterns

New Feature

1. Define data model → Developer
2. Implement business logic → Developer
3. Create API endpoint → Developer
4. Write unit tests → Integrator
5. Write e2e tests → Integrator
6. Update documentation → Architect

Bug Fix

1. Reproduce and document → Developer
2. Implement fix → Developer
3. Add regression test → Integrator
4. Verify fix → Architect (review)

Refactoring

1. Document current behavior with tests → Integrator
2. Refactor implementation → Developer
3. Verify tests still pass → Integrator
4. Review architecture impact → Architect