Systematic three-phase approach to feature development using Requirements, Design, and Tasks phases. Transforms vague feature ideas into well-defined, implementable solutions that reduce ambiguity, improve quality, and enable effective AI collaboration.

Spec Driven Development A comprehensive methodology for systematic software feature development that ensures quality, maintainability, and successful delivery through structured planning. When to Use This Skill Ideal scenarios: Complex features with multiple components, integrations, or user interactions High stakes projects where rework costs are significant Team collaboration requiring shared understanding AI assisted development where clear structure improves output quality Knowledge preservation for future maintainers Less suitable: Simple bug fixes with obvious solutions Experimental prototypes for rapid iteration Time critical hotfixes requiring immediate action Well established patterns with minimal ambiguity The Three Phase Workflow Phase 1: Requirements Gathering Purpose: Transform vague feature ideas into clear, testable requirements Process: 1. Capture user stories expressing value and purpose 2. Define acceptance criteria using EARS format (Easy Approach to Requirements Syntax) 3. Identify edge cases and constraints 4. Validate completeness and feasibility EARS Format Patterns: Example: Phase 2: Design Documentation Purpose: Create a comprehensive technical plan for implementation Process: 1. Research technical approaches and constraints 2. Define system architecture and component interactions 3. Specify data models and interfaces 4. Plan error handling and testing strategies Design Document Structure: Decision Documentation: Phase 3: Task Planning Purpose: Break design into actionable, sequential implementation steps Process: 1. Convert design elements into specific coding tasks 2. Sequence tasks to enable incremental progress 3. Define clear objectives and completion criteria 4. Reference requirements for traceability Task Structure: Task Sequencing Strategies: Foundation First: Core interfaces before dependent components Feature Slice: End to end vertical slices for early validation Risk First: Tackle uncertain areas early Hybrid: Combine approaches based on project needs Quality Checklists Requirements Checklist [ ] All user roles identified and addressed [ ] Normal, edge, and error cases covered [ ] Requirements are testable and measurable [ ] No conflicting requirements [ ] EARS format used consistently Design Checklist [ ] All requirements addressed in design [ ] Component responsibilities well defined [ ] Interfaces between components specified [ ] Error handling covers expected failures [ ] Security considerations addressed Tasks Checklist [ ] All design components have implementation tasks [ ] Tasks ordered to respect dependencies [ ] Each task produces testable code [ ] Requirements references included [ ] Scope is appropriate (2 4 hours each) Integration with AI Workflows For Claude Code / AI Assistants: 1. Start with context: Provide project background, constraints, and goals 2. Work in phases: Complete requirements before design, design before tasks 3. Iterate: Refine outputs through conversation rather than single requests 4. Validate: Ask AI to review outputs against checklists 5. Trace: Maintain links between requirements, design, and tasks Example prompt for starting a spec: Common Pitfalls to Avoid 1. Skipping phases: Each phase builds on the previous; shortcuts create problems 2. Vague requirements: "System should be fast" vs specific, measurable criteria 3. Implementation details in requirements: Focus on what, not how 4. Over engineering design: Solve current requirements, not hypothetical future ones 5. Monolithic tasks: Break down into 2 4 hour increments 6. Missing error cases: Always consider what happens when things go wrong Next Steps After completing a spec: 1. Begin implementation following task sequence 2. Track progress by marking tasks complete 3. Update spec if implementation reveals gaps 4. Validate completed work against requirements 5. Document learnings for future specs

spec-driven-development