This handles the messy reality of upgrading old codebases without breaking production. It walks you through framework migrations like jQuery to React or Python 2 to 3, guides you on adding tests to untested legacy code, and helps decompose monoliths using the strangler fig pattern. The focus is explicitly on risk mitigation and backward compatibility, with feature flags, rollback procedures, and compatibility shims baked into the approach. It's most useful when you inherit a codebase with technical debt and need a structured migration plan rather than a risky big bang rewrite. The outputs include phased migration plans and deprecation timelines, which is exactly what you need when stakeholders are nervous about touching anything.
npx skills add https://github.com/sickn33/antigravity-awesome-skills --skill legacy-modernizer