Agent skill · software engineering · pedronauck
lesson-learned
Analyze recent code changes via git history and extract software engineering lessons. Use when the user asks 'what is the lesson here?', 'what can I learn from this?', 'engineering takeaway', 'what did I just learn?', 'reflect on this code', or wants to extract principles from recent work.
Why this skill is useful
Adds a structured analysis framework for extracting actionable software engineering lessons from git history that the AI wouldn't generate on its own.
What it needs
About 3k tokens when loaded. Last updated 2026-08-01. 564 stars on the source repository.
What this skill does
Lesson Learned Extract specific, grounded software engineering lessons from actual code changes. Not a lecture -- a mirror. Show the user what their code already demonstrates. Before You Begin Load the principles reference first. 1. Read references/se-principles.md to have the principle catalog available 2. Optionally read references/anti-patterns.md if you suspect the changes include areas for improvement 3. Determine the scope of analysis (see Phase 1) Do not proceed until you've loaded at least se-principles.md. Phase 1: Determine Scope Ask the user or infer from context what to analyze. Scope Git Commands When to Use ------- ------------- ------------- Feature branch git log main..HEAD --oneline + git diff main...HEAD User is on a non-main branch (default) Last N commits git log --oneline -N + git diff HEAD~N..HEAD User specifies a range, or on main (default N=5) Specific commit git show <sha> User references a specific commit Working changes git diff + git diff --cached User says "what about these changes?" before committing Default behavior: If on a feature branch: analyze branch commits vs main If on main: analyze the last 5 commits If the user provides a different scope, use that Phase 2: Gather Changes 1. Run git log with the determined scope to get the commit list and messages 2. Run git diff for the full diff of the scope 3. If the diff is large (>500 lines), use git diff --stat first, then selectively read the top 3-5 most-changed files 4. Read commit messages carefully -- they contain intent that raw diffs miss 5. Only read changed files. Do not read the entire repo. Phase 3: Analyze Identify the dominant pattern -- the single most instructive thing about these changes. Look for: Structural decisions -- How was the code organized? Why those boundaries? Trade-offs made -- What was gained vs. sacrificed? (readability vs. performance, DRY vs. clarity, speed vs. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills pedronauck/lesson-learned