# Working Effectively with Legacy Code by Michael Feathers

16 Hacker News commenters recommended Working Effectively with Legacy Code by Michael Feathers and 1 criticized it, November 2025 to November 2026. It was recommended in 8 of 13 months. It meets the Hacker Approved badge rule.

**Verdict:** Practical, step-by-step guide to changing untested legacy code safely, with techniques like seams and cut points that people still use daily.

## Why people recommend it

- Practical, actionable techniques for legacy code (3 comments): "It is the best step by step guide I have ever seen to successfully work with legacy code." ([source](https://news.ycombinator.com/item?id=47227474)) "Usually there is something in there I can apply directly to get me out of a pinch." ([source](https://news.ycombinator.com/item?id=48045699)) "it's both pragmatic and actionable" ([source](https://news.ycombinator.com/item?id=45975814))
- Recommended as the standard reference (4 comments): "The exact same approach is recommended in the book "Working effectively with legacy code" by Michael Feathers, with several techniques on how to do it." ([source](https://news.ycombinator.com/item?id=47624452)) "This is the general approach advocated by Feathers' Working Effectively with Legacy Code book" ([source](https://news.ycombinator.com/item?id=46878576)) "you should probably start from _Working Effectively with Legacy Code_ by Michael Feathers" ([source](https://news.ycombinator.com/item?id=47609686))
- Seams and cut points for testing (2 comments): "he discusses using cut points to build a testing firewall to bring code under test" ([source](https://news.ycombinator.com/item?id=48054848)) "found the concept of "seams" from that book useful" ([source](https://news.ycombinator.com/item?id=47959538))
- Changes how to think about old code (2 comments): "It will certainly be eye-opening to some, as it dispels the myth that legacy code is a function of age." ([source](https://news.ycombinator.com/item?id=46203294)) "It changed my approach to how to think about old code-bases." ([source](https://news.ycombinator.com/item?id=47958714))

## Alternatives hackers recommend

- [Crafting Interpreters by Robert Nystrom](https://hackerapproved.com/p/crafting-interpreters.md): 60 recommend
- [Clean Code by Robert C. Martin](https://hackerapproved.com/p/clean-code.md): 31 recommend
- [The Pragmatic Programmer by Hunt and Thomas](https://hackerapproved.com/p/pragmatic-programmer.md): 28 recommend
- [How to Design Programs by Felleisen, Findler, Flatt and Krishnamurthi](https://hackerapproved.com/p/how-to-design-programs.md): 18 recommend
- [Mastering Emacs by Mickey Petersen](https://hackerapproved.com/p/mastering-emacs.md): 17 recommend

## Where to get it

- [See price on Amazon](https://www.amazon.com/dp/0132931745?tag=hackerapprove-20) (affiliate link)
- [Bookshop.org](https://bookshop.org/a/130825/9780132931748) (affiliate link)

## Cite as

Hacker Approved, "Working Effectively with Legacy Code by Michael Feathers", https://hackerapproved.com/p/working-effectively-with-legacy-code/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).