[aw1621107]

> The kind of thing you can verify at compile-time can be tested very quickly

I’m not sure I entirely agree with this. For example, a type system can ensure a function is always called with the right units, but testing that every use of the function is correct might be a lot more tedious, depending on the code base.

> and compilers with less useful type systems can be much faster.

This depends very heavily on the language (e.g., OCaml being a language with a relatively complex type system that also compiled fairly quickly), but Id agree that what you said appears to be the general trend.