Define "mission critical". Are people going to die if bugs get shipped? If so, be aware that static type checking will not get you there alone, but it should be

Define "mission critical". Are people going to die if bugs get shipped? If so, be aware that static type checking will not get you there alone, but it should be considered mandatory. Beyond that: If your team is most familiar with Python, it is probably best to stick with Python. http://mypy-lang.org/ http://mypy-lang.org/ might be the best option: you get static type checking for new code, you can add static type checking to your existing codebase, and you get to use something you're already familiar with. I recommend reading http://boringtechnology.club/ http://boringtechnology.club/ - especially the "let's switch" part.