One Day Build
Production-ready project foundation in a single session (5-8 hours).
Philosophy: Architecture first → Document decisions → Refactor ruthlessly → Test what differs
Quick Reference
| Phase | Duration | Focus | Exit Criteria |
|---|---|---|---|
| 1. Intent | 30 min | What & Why | 3-5 user stories documented |
| 2. Architecture | 60-90 min | How | AGENTS.md with decisions |
| 3. Foundation | 2-3 hrs | Build | 1 feature working, >80% coverage |
| 4. Refinement | 1-2 hrs | Fix | Bugs fixed, code cleaned |
| 5. Testing | 60 min | Verify | Test factories, fast suite |
| 6. Docs | 30 min | Record | README + AGENTS.md current |
Phase Workflow
1. Intent Clarification
Ask clarifying questions until requirements are concrete:
- •Vision, constraints, tech preferences?
- •Must-have vs nice-to-have?
- •Sample data available?
User: "I want to build a stock price tracker" → "Which APIs? Real-time or daily? CLI, web, or both? Alerts needed?" → Result: Yahoo Finance API, daily updates, CLI + web dashboard, email alerts
Checklist: [ ] 3-5 user stories [ ] Constraints doc [ ] Priority list
2. Architecture Design
Propose 2-3 approaches with trade-offs. Document in AGENTS.md.
Key decisions:
- •Patterns: Template Method (workflows), Strategy (algorithms), Factory (creation)
- •Extensibility: How to add new data sources/formats?
- •Config: What's configurable vs hardcoded?
Checklist: [ ] AGENTS.md created [ ] Interfaces defined [ ] Config schema
3. Foundation Implementation
- •Setup (15 min) - structure, deps, git
- •Core (45 min) - base classes, error handling
- •First feature (60 min) - complete with real data
- •Tests (30 min) - fixtures, >80% coverage
Checklist: [ ] 1 feature works [ ] Tests pass [ ] Makefile ready
4. Problem-Driven Refinement
Cycle: Discover → Analyze → Design → Implement → Validate
Only refactor when problems emerge. Don't pre-optimize.
Bug: Year 1948 showing as 2025 → Root cause: No year validation → Fix: Add _is_valid_year() + test
Checklist: [ ] Bug fixed [ ] Regression test added [ ] Docs updated
5. Testing Architecture
Goal: Make testing easier than not testing.
# Factory pattern - one line = full test suite TestStockFetcher = create_fetcher_tests(StockFetcher, sample_data, expected)
Checklist: [ ] Test utilities exist [ ] <5s run time [ ] >80% coverage
6. Documentation Sync
Maintain: AGENTS.md (decisions), TODO.md (backlog), README.md (usage)
Principle: If not documented, it doesn't exist.
Checklist: [ ] Examples work [ ] Decisions recorded [ ] Next steps clear
Roles
| Agent | Human |
|---|---|
| Propose options with trade-offs | Choose direction |
| Implement and test | Provide domain knowledge |
| Document decisions | Validate against real use |
| Challenge assumptions | Accept/reject trade-offs |
Variations
| Scenario | Use Phases |
|---|---|
| Greenfield | 1-6 (full) |
| Legacy refactor | 3-5 |
| Feature addition | 2-5 |
| Bug hunt | 4-5 |
Anti-Patterns
| Problem | Fix |
|---|---|
| Analysis paralysis | Time-box design to 90 min |
| Premature optimization | Solve today's problems only |
| Doc debt | Document decisions immediately |
| Scope creep | Add to TODO.md, stay focused |
For detailed role breakdowns and examples, see references/phases.md.