In their book “The Mikado Method”, Ola Ellnestam and Daniel Brolund explain the Mikado method, a method for structurally approaching non-trivial technical improvements to any large scale legacy system.
The main artefact of using the method is the so called Mikado Graph, which is typically drawn on a piece of paper. After drawing many of these on paper, I fell in love with the method. But I also wanted a way to more easily change these graphs, link to code sections, and share them with team members, for example by attaching them to pull requests.