majiayu000 Phase Decomposition
Instructions
Create 3-8 phases
Each phase:
- Has clear deliverable
- Takes 30min - 2 hours
- Is independently testable
- Has clear success criteria
Decomposition process
- Identify core components
- Order by dependency
- Split into phases
- Define success criteria for each
Example
Feature: "Add {{entity}} validation"
Phase 1: Schema (30min)
- Deliverable: ValidationSchema class
- Test: Schema creation works
Phase 2: {{Field1}} Validation (45min)
- Deliverable: validate_{{field1}}() method
- Test: Rejects invalid {{field1}} values
Phase 3: {{Field2}} Validation (45min)
- Deliverable: validate_{{field2}}() method
- Test: Rejects invalid {{field2}} values
Phase 4: Integration (1hr)
- Deliverable: {{Entity}}Validator service
- Test: Full validation workflow
Domain-Specific Examples
E-commerce: Payment Processing
Feature: "Implement payment processing"
Phase 1: Payment Gateway Integration (1.5hr)
- Deliverable: PaymentGateway client wrapper
- Test: Can connect to gateway API
Phase 2: Transaction Creation (1hr)
- Deliverable: createTransaction() method
- Test: Creates transaction record
Phase 3: Payment Verification (1.5hr)
- Deliverable: verifyPayment() method
- Test: Validates payment status from gateway
Phase 4: Webhook Handler (1hr)
- Deliverable: Payment webhook endpoint
- Test: Processes payment status updates
Phase 5: Refund Logic (1.5hr)
- Deliverable: processRefund() method
- Test: Refunds work correctly
SaaS: User Authentication
Feature: "Add user authentication"
Phase 1: User Model & Database (45min)
- Deliverable: User table schema
- Test: Can create/read users
Phase 2: Password Hashing (30min)
- Deliverable: hashPassword() and verifyPassword()
- Test: Passwords hashed securely
Phase 3: Login Endpoint (1hr)
- Deliverable: POST /auth/login
- Test: Returns JWT on valid credentials
Phase 4: Token Validation (1hr)
- Deliverable: Authentication middleware
- Test: Rejects invalid/expired tokens
Phase 5: Logout & Token Revocation (45min)
- Deliverable: POST /auth/logout
- Test: Invalidates tokens properly
Data Platform: ETL Pipeline
Feature: "Build data extraction pipeline"
Phase 1: Data Source Connector (1.5hr)
- Deliverable: SourceConnector class
- Test: Can fetch raw data
Phase 2: Data Parser (1hr)
- Deliverable: parseData() method
- Test: Converts raw data to structured format
Phase 3: Data Validation (1.5hr)
- Deliverable: validateData() method
- Test: Rejects malformed data
Phase 4: Data Transformation (2hr)
- Deliverable: transformData() method
- Test: Applies business logic correctly
Phase 5: Data Storage (1hr)
- Deliverable: saveData() method
- Test: Persists to database
Phase 6: Error Handling & Retry (1hr)
- Deliverable: Retry mechanism
- Test: Recovers from transient failures
IoT: Device Management
Feature: "Implement device registration"
Phase 1: Device Model (45min)
- Deliverable: Device table schema
- Test: Can create device records
Phase 2: Registration Endpoint (1hr)
- Deliverable: POST /devices/register
- Test: Creates device with unique ID
Phase 3: Device Authentication (1.5hr)
- Deliverable: Device token generation
- Test: Devices can authenticate
Phase 4: Device Status Tracking (1hr)
- Deliverable: updateStatus() method
- Test: Tracks online/offline status
Phase 5: Device Configuration (1hr)
- Deliverable: Device config API
- Test: Can update device settings
CRM: Contact Management
Feature: "Add contact import"
Phase 1: File Upload Handler (1hr)
- Deliverable: POST /contacts/import
- Test: Accepts CSV/Excel files
Phase 2: File Parser (1hr)
- Deliverable: parseContactFile() method
- Test: Extracts contact data
Phase 3: Contact Validation (1.5hr)
- Deliverable: validateContact() method
- Test: Validates email, phone, required fields
Phase 4: Duplicate Detection (1.5hr)
- Deliverable: findDuplicates() method
- Test: Identifies existing contacts
Phase 5: Bulk Insert (1hr)
- Deliverable: bulkCreateContacts() method
- Test: Efficiently inserts contacts
Phase 6: Import Report (45min)
- Deliverable: Import summary response
- Test: Reports success/failure counts
Anti-Patterns to Avoid
❌ Too Large (Unmanageable)
Phase 1: Build entire authentication system (8hr)
- Too big, can't test incrementally
- High risk of delays
❌ Too Small (Excessive Overhead)
Phase 1: Define constant (5min)
Phase 2: Write validation if-statement (5min)
Phase 3: Add error message (5min)
- 15 phases for simple feature
- Workflow overhead too high
❌ Wrong Dependencies
Phase 1: Frontend UI
Phase 2: Backend API ← Depends on Phase 1
- Wrong order! Backend should come first
✅ Correct Example
Phase 1: Backend API (1hr)
- Can test independently
Phase 2: Frontend UI (1.5hr)
- Consumes Phase 1 API
- Dependency order correct
Checklist
Before finalizing phases:
- Each phase 30min - 2hr?
- Total 3-8 phases?
- Dependencies ordered correctly?
- Each phase independently testable?
- Clear deliverable for each?
- Success criteria defined?
For detailed patterns, see reference.md For more examples, see examples.md