One counterintuitive observation about introducing stricter type checking into an existing codebase is that it rarely finds bugs. Why? Because the existing co

One counterintuitive observation about introducing stricter type checking into an existing codebase is that it rarely finds bugs. Why? Because the existing codebase typically "already works", in that issues that the type checker might have found were already discovered through automated (or manual!) testing. The real value of more strict type checking is when writing new code -- you won't need to spend as much time discovering bugs in development or writing tests for issues the compiler is catching.