"team is 3 people" and "this code generates more than 20 million dollars a year of revenue" Whatever else you do, I hope you and the organization figure out ho

"team is 3 people" and "this code generates more than 20 million dollars a year of revenue" Whatever else you do, I hope you and the organization figure out how to celebrate that those three people are generating 20 million dollars of revenue (or at least keeping part of the machinery that does that running. "I know a full rewrite is necessary, but how to balance it?" Well, maybe... How much code is it? How much traffic does it receive? ---- I would be looking at https://martinfowler.com/bliki/BranchByAbstraction.html https://martinfowler.com/bliki/BranchByAbstraction.html or https://martinfowler.com/bliki/StranglerFigApplication.html https://martinfowler.com/bliki/StranglerFigApplication.html