I think this is the most forgotten part of this type of issue. It's not a static issue. With these types of things and time the problem often gets worse, and th

I think this is the most forgotten part of this type of issue. It's not a static issue. With these types of things and time the problem often gets worse, and the answers get easier. They should be periodically re-evaluated. Parts of the problem get worse as time goes on. (more code to convert, more complexity, more test cases, EOL for the python2 version of some lib, more user data, blah) Parts of the solution get easier as time goes on. (easier syntax sugars, better testing frameworks, infrastructure abstracted easier, remove dead features, etc) Parts of the desired solution become less relevant as time goes on. (Why not use golang or node or elixir, php and python are so dated!)... Just because last year was a bad time for the upgrade doesn't mean today is. Knowing how to get these things done at the right time by the right people for the business is what separates a great engineering manager from one that is just "shipping features and bug fixes".