Apply Michael Feathers-inspired legacy-code rules when changing hard-to-test code safely with characterization tests, seams, sprout methods, or wrap methods.
Pro scans all 4 files and shows the line behind each finding
Scanned 9/22/2026
Skills Directorynpx -y skills add ciembor/agent-rules-books --skill working-effectively-with-legacy-code --agent claude-codeInstalls into .claude/skills of the current project.
Are you the author of Working Effectively With Legacy Code?
Add the live security badge to your README — it updates automatically with every re-scan.
[](https://www.skillsdirectory.com/skills/ciembor-working-effectively-with-legacy-code)More formats (shields.io, HTML) on the badges page. Keep it an A: scan every change in CI with Pro.
---
name: working-effectively-with-legacy-code
description: Apply Michael Feathers-inspired legacy-code rules when changing hard-to-test code safely with characterization tests, seams, sprout methods, or wrap methods.
license: MIT
---
# Working Effectively with Legacy Code Skill
Use this skill when a task involves risky legacy changes, missing tests, characterization tests, seams, dependency breaking, sprout method, wrap method, or incremental risk reduction.
Before making design or code decisions, read and apply [working-effectively-with-legacy-code.mini.md](working-effectively-with-legacy-code.mini.md). Use [working-effectively-with-legacy-code.md](working-effectively-with-legacy-code.md) only as a deeper reference when the mini rules are not enough for the current legacy-code tradeoff.
Is this your skill, or is something wrong with this listing? Request removal or report an issue. Author removals are honored within 72 hours.
No comments yet. Be the first to comment!
