We tried adding MyPy type hints to a few thousand lines of reasonably hairy production code. This talk will discuss some of the challenges that we encountered, how we dealt with them, what we learnt, and whether we thought it was worth all the effort. (Spoiler: we did think it was worth all the effort.)

I won't have time to give a full overview of MyPy, but I will try to cover enough basics that the talk is mostly accessible to people who aren't already familiar with it.