Comment by raphinou

Sure thing. Cheers!

Typically, "static typing" refers types being checked at compile time rather than runtime; in other words, the analysis can happen before the program is run, which gives you some degree of confidence in what the behavior will be when actually running it. The opposite of this is "dynamic typing", which means that the type-checking happens while the program is running, so you don't have the up-front guarantee that you won't end up having an error due to the wrong type being used somewhere. In practice, this isn't a strict binary where a language has to be 100% static or 100% dynamic. For example, Java is mostly statically typed, but there are some cases where things are a bit more dynamic (e.g the compiler allowing certain casts that might not end up being successful at runtime, at which point they throw an exception). On the other hand, Python traditionally has been a dynamically typed language, but in recent years there have various efforts to allow type annotations that allow checking some things in advance, which moves it a bit in the static direction (I'm not familiar enough with the current state of things in the ecosystem to have any insight into how much this has moved the needle).

On the other hand, "strong typing" isn't as quite as standardized in type systems terminology, but broadly speaking, it tends to be used to describe things like how "sound" a type system is (which is a well-defined concept in type systems theory), whether or not implicit type coercions can occur in the language, or other things that roughly translate to whether or not its possible for things to get misused as the wrong type without an explicit error occurring. Two examples that are commonly cited are JavaScript[0], with its sometimes confusion implicit conversions to allow things like adding an empty object and an empty array and getting the number 0 as the result (but not if added in the other order!) and C, with it being possible to interpret a value as whatever the equivalent underlying bytes would represent in an arbitrary type depending on the context its used.

[0]: I normally don't like to link to videos, but this famous comedic talk demonstrating a few of these JavaScript quirks is so thoroughly entertaining to watch again every few years that I feel like it's worth it so that those who haven't seen it before get a chance: https://www.destroyallsoftware.com/talks/wat

strong typing: 2 + "2" is an error (e.g. Python vs JS)

static typing: 2 + "2" does not compile/parse (e.g. Python vs mypy, Typescript vs JS)

this is a very simplistic example, but should get you to feel the difference.

The appeal is the runtime model. I can’t readily verify if BEAM languages are meaningfully slower or really slower at all but let’s take the premise for the sake of argument.

Even if is slower, the runtime model is incredibly resilient and it’s cheap to scale up and down, easy to hot update, and generally does asynchronous work extremely well across a lot of different processes.

F# has really good async ergonomics but it doesn’t have the same task/processing flexibility and Websockets are kind of a pain compared to elixir or even erlang

For most of the workloads you’re putting on the BEAM, they are IO bound and this is not of any consequence