Type checking helps make the code base more maintainable, but given that there is a lot of existing code, it's less feasible to add types all at once.

• Choose a type checking tool
• configure the tool in such a manner that we can add types one file at a time, essentially ratcheting the checking over time. Once a file becomes typed, CI should ensure it stays that way.
• As an initial step, add types to at least one file to demonstrate feasibility of this approach. Over time, continue adding types