I once converted a fairly large JS codebase to TS and I found about 200 mismatching names/properties all over the place. Tons of properties we had nulls suddenly started getting values.
Although, an esoteric language defined in terms of negative space might be interesting. A completely empty source file implements “hello world” because you didn’t write a main function. All integers are incremented for every statement that doesn’t include them. Your only variables are the ones you don’t declare. That kind of thing.
Oh I forgot to qualify that I'm only talking about high level code, not things that you'd use C or Rust for. But part of the reason those langs have static types is they need to know sizes on stack at compile time.