• JetBrains / Guide / Refactoring
• freeCodeCamp.org / How to Refactor Complex Codebases – A Practical Guide for Devs about isolating issues, breaking down monolithic code, testing

Wiki

• Code refactoring
• Корабль Тесея
• Duplicate code

GitHub

• openrewrite/rewrite Automated mass refactoring of source code.
  • docs

Courses

• Jon Pearce
  • Lectures
    • Refactoring