system-architecture
Installation
SKILL.md
System Architecture
Purpose
Architecture decisions are the most expensive decisions in software development because they are the hardest to reverse. This skill's job is to force explicit reasoning about trade-offs before code is written. A 1-hour architecture session prevents a 3-week refactor.
SOP: Architectural Design
Step 1 - NFR Analysis (Non-Functional Requirements)
Before drawing any boxes, define the performance envelope. Fill this matrix:
| NFR | Target | Notes |
|---|---|---|
| Latency (P95) | e.g., < 200ms API response | Based on user expectations |
| Throughput | e.g., 100 req/s at launch, 1000 req/s in 12 months | Drives horizontal scaling decision |
| Availability | e.g., 99.9% (8.7hr downtime/year) | Drives redundancy design |
| Consistency | e.g., Strong (banking) vs Eventual (social feed) | Drives DB and cache choices |
| Data Retention | e.g., 7 years for compliance, 30 days for session data | Drives storage architecture |
If these targets are unknown, ask the user. Most vibe-coders will say "fast" and "always on" - help them translate this into concrete numbers.