architecture-decision

# Architecture Decision Skill ## Core Philosophy: "Everything is a Trade-off" There are no "best solutions", only solutions with the right set of trade-offs for the specific context. ## Decision Making Process (RFD / RFC) 1. **Context**: What is the problem? Why now? 2. **Constraints**: Budget, Time, Skillset, Legacy. 3. **Options**: Propose at least 3 viable options. 4. **Trade-off Analysis**: Compare constraints vs options. 5. **Recommendation**: Choose one and justify. ## Trade-off Analysis Matrix (Template) | Feature | Option A (e.g. SQL) | Option B (e.g. NoSQL) | Option C (e.g. File) | |---------|---------------------|-----------------------|----------------------| | **Scalability** | Medium (Vertical) | High (Horizontal) | Low | | **Consistency** | Strong (ACID) | Eventual (BASE) | N/A | | **Complexity** | Low (Known) | Medium (New tech) | Low | | **Cost** | $$ | $$$ | $ | ## Architecture Note When a decision is made, document it. ```markdown # Architecture Note: Use PostgreSQL for Main Database ## Status Accepted ## Context We need a reliable, relational database for user data... ## Decision We will use PostgreSQL 16. ## Consequences - Positive: ACID compliance, rich ecosystem. - Negative: Scaling writes requires sharding later. ``` ## Critical Factors to Evaluate - **Reliability** (Availability, Fault tolerance) - **Scalability** (Throughput, Latency) - **Maintainability** (Simple vs Easy, Ecosystem) - **Security** (AuthN/Z, Encryption) - **Cost** (Infrastr...