# Retrospective

## Milestone: v1.0 — MVP

**Shipped:** 2026-03-26
**Phases:** 4 | **Plans:** 11 | **Timeline:** 3 days (2026-03-24 -> 2026-03-26)
**LOC:** 3,254 Go | **Files:** 84 modified

### What Was Built
- Config-driven packet classifier with 12 protocol rules and 4 hash-bucketed unknown classes
- Live packet capture via pure Go go-pcap with privilege detection and non-blocking channel pipeline
- Additive synthesis engine: per-class oscillators, EMA amplitude smoothing, constant-power stereo mixing
- MP3 encoding via embedded LAME, zero-packet guard
- End-to-end pipeline with clean Ctrl+C shutdown
- BPF filter and offline pcap file sonification with timestamp-based windowing

### What Worked
- Risk-ordered phases: hardest foundation first (capture), then synthesis in isolation, then integration — no phase blocked on another's bugs
- TDD approach in executor agents caught signature mismatches early
- Pure Go capture layer (go-pcap) avoided libpcap dependency headaches
- Hand-rolled synthesis kept dependencies minimal and code understandable
- Wave-based parallel execution for independent plans

### What Was Inefficient
- Some SUMMARY.md files had empty one-liner fields, causing noisy milestone extraction
- Phase 4 research could have been lighter — BPF/pcap APIs were straightforward

### Patterns Established
- Ordered []Rule slice for classifier (first-match-wins, extensible)
- io.Writer injection for testable stderr output
- Buffered channels between pipeline stages (512-1024) to absorb bursts
- Package-level globals for Cobra flag binding
- Timestamp-based windowing for non-live sources

### Key Lessons
- Embedding C source (go-lame) is a good tradeoff: CGo at build time only, no runtime dependency
- go-audio/wav was unnecessary — writing PCM bytes directly to LameWriter is simpler
- Hash-bucketed unknowns (4 classes) are sufficient for audio distinction without k-means complexity

## Cross-Milestone Trends

| Metric | v1.0 |
|--------|------|
| Phases | 4 |
| Plans | 11 |
| Days | 3 |
| LOC | 3,254 |
| Avg plan duration | ~8 min |