When I hit ctrl+save, the code should be instantly ready to test, less than 200ms. Waiting for 30 seconds to see code is an ETERNITY to people that code fast, 1k lines per day. I have been on teams that wait 5m to test code, what a waste. Fast feedback loops in code are critical, just like design, or anything important. Types seem like some weird religion, the people that use them cannot be talked out of it.
30+ second compile times is definitely not something inherent to statically typed languages. 200ms is rare, but plenty of static languages manage <5s for large projects and much less for small ones. Not to mention that a good IDE will incrementally check types in well under a second as you type, so the need for frequent test runs is lower.
That said, I agree 100% about the importance of fast feedback loops.
I highly recommend you to check out ReScript. Amazingly fast compile times.
Watching typescript teams spent 30 seconds on the recompile is insane for me.
in fact, the whole ocaml family of programming languages are mega fast.
The most important feature of a very fast compile time is that you can load it with types after types and write in your whole mental model, without worrying about your build process slowing down.
in my experience dynamically typed languages are slower to compile than dynamic ones. groovy, for example, is massively slower to compile than java (it is something like a factor of 10x in our codebase), and the whole point is literally to give you python-style code velocity.
that's not to say that you can't write slow statically-typed compilers. but the strict syntax tree gives you much faster parsing/etc. dynamic languages can't avoid this either, it just does it at runtime instead.
and hot-reload for function changes/etc is very possible in a similar fashion to dynamic compilers too. And if you add a space or a bracket, because of the parsing problem, you can't even notionally contain that to a single part of the AST, the whole thing has to be re-parsed.
again, not that you can't make a static language compile very slowly, or that any given implementation is necessarily faster. but dynamic languages almost strictly have to do more parsing work, and have to do it more often, over larger parts of the codebase. and that's expected - static languages offload some of this "preprocessing" to the developer!
