# Lessons

> Extract software engineering principles, takeaways, and anti-patterns from recent commits or diffs. Short command alias for lessons-learned.

- Skill: `shalomb/lessons` (Agent Skill)
- Install (CLI): `npx skillmds@latest add shalomb/lessons`
- Raw SKILL.md: https://api.skillmd.com/api/skills/shalomb/lessons/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: shalomb (https://skillmd.com/u/shalomb)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/shalomb/lessons

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# Lessons Learned Retrospective (/lessons)

<!-- generated:alias-skill -->
When invoked, load and execute the **`lessons-learned`** skill:
1. Follow all instructions and guidelines in [`lessons-learned`](../lessons-learned/SKILL.md).
2. Determine analysis scope: feature branch (`git log main..HEAD` + `git diff main...HEAD`), last N commits, or specific SHA.
3. Load core software engineering principles catalog from `references/se-principles.md` and `references/anti-patterns.md`.
4. Extract actionable, grounded software engineering lessons demonstrating what the code changes prove or caution against.