What if the development team is not by a bus? What if they're suddenly replaced with chimpanzees? Literally collecting all the problems with the current code b

What if the development team is not by a bus? What if they're suddenly replaced with chimpanzees? Literally collecting all the problems with the current code base and designing around them is the only thing anyone can reasonably do. If you have a poor development team, you're just screwed - hire a better one. The problem there is figuring whom you can keep and in which position. Since nobody knows how to grade programmers (and stupid algorithmic tests do not work for design and engineering which is critical) you get to try until you run out of money and perhaps rely on peer or expert opinion. As a point of reference, rewriting a GUI with a layout engine (not a web browser but a music editor, shares a lot of design) took a small team half a year and solved all of the problems reported and a bunch of others. Including performance. At 4 months we had an almost matching result with exclusion of single issues that took additional redesign. (Asked client if they already want to keep it, they said to finish it.) And the testing was limited to manual checklists. A web browser is bigger and testing somewhat easier to automate. The true important thing we did is dig into requirements including fuzzy ones and designed using good practices making change easy. (Including a few times when the client just changed the requirements.)