Jakob wants to give this talkHow to plan and perform improvements on legacy systems
I've recently read the book "The Mikado Method" from Ola Ellnestam and Daniel Brolund who describe a pragmatic but very effective method to work with legacy code. Inspired by the book we've applied the technique to work on a (yet not published) feature at GitHub.
As I think every developer should know about this technique I'm more than happy to present the core principles of the "Mikado Method".