Moving from TypeScript to Rust / WebAssembly (opens in new tab)

I’ve worked on several large Ruby codebases, and the thing is, the same qualities that make it easy to get a Ruby project up and working quickly make it a complete nightmare to maintain later. Its expressiveness and malleability mean that you can never really be sure that you understand how code is being used, and the complexity that emerges from a few years of that is incredibly overwhelming. Nowadays I would much rather slog through ten times as much Java boilerplate, because later I’d expect that I could still refactor code without fearing that the whole thing would collapse around me

Won ? Ruby fell off a cliff once it got to a point where people had to maintain that shit in production - I'm currently working on a large mature RoR codebase and I'm switching jobs ASAP because it's incredibly painful to work with and feels like a dead end career wise - and I like the gig otherwise - good product and a decent team - but the technology is draining so much of my life energy on nonsense it's ridiculous. And the language is built for unmaintainability - standard functions being abbreviated to a single letter, 2 or 3 aliases for a single standard function (map/collect and such), Rails overriding the conventions of the language (! postfix). And then there's the architectural retardation of fat models, fat controllers and using mixins ("concerns") completely break encapsulation - all actively killing code reuse-

PHP has long been a meme and is mostly legacy stuff or bottom tier work.

Dynamic languages are adding static optional static typing because the value provided by tooling as the projects scales is undeniable.

It took ES6/TypeScript to drag JS out of the dump that it was with every library adding its own take on a class system - the maintainability jump from ES5 to TS is incomparable for anything larger than 1k LOC

They've "won" so far because static types languages were cumbersome and unpleasant to use, but this is changing and dynamic languages are learning some type tricks too.

The issue here is with Rust: its strengths are mostly irrelevant for the web and its weaknesses (particularly slow development compared to the competition because of having to pacify the type checker) are really important.

Op is painstakingly beating around the bush, but what they're getting at is that Rust + webdev = mismatch.

> This really nails why languages like PHP and Ruby have won out over static typed

It really doesn't.

Languages like PHP and Ruby "have won out" over statically typed languages because the representatives of statically typed languages at the time were Java and C++, both of which were bad (they still are, but they were): verbose, difficult (and verbose) to leverage for type-safety, missing a bunch of tremendously useful pieces (type-safe enums to say nothing of full-blown sum types), nulls galore, …

As a result, the gain in expressiveness and terseness (even without trying to code-golf) of dynamically typed languages was huge, the loss in type-safety was very limited given the choice was "avoid leveraging the type system" or "write reams of code because the language is shit", and the fast increase in compute performances more than compensated for the language's loss in efficiency.

And that's before talking about the horror show that Java's web frameworks ecosystem was circa 2006.

> Languages that tend to work well with it are those that are highly flexible around the corner cases of these technologies, and allow you to quickly iterate through the process of gluing them together.

That's really complete hogwash outside of the client, which isn't what we're talking about here since neither php nor ruby run there. On the server you have clear interfaces between "inside" and "outside", and there's no inflexibility to properly taking care of cleaning up your crap at the edges. Quite the opposite, really.

I think you get it backwards. Things are disjointed, loosely coupled because highly dynamic languages have won. The flexibility of dynamic languages, which can be great when working around dynamic corner cases, does not force developers into fixed, well-defined contracts keeping everything loose and disjoint.

PHP is highly to blame. PHP, being a scripting language, is easy to deploy and keeps chugging along at all costs. It may do something nonsensical, but it will try to chug along to completion without aborting. It creates a system where it is easy to write and deploy something that usually works.

Having ridden the 90's .com startup wave with an in-house application server written in a mix of Apache plugins and Tcl, I learned the hard way to never again rely on anything that doesn't bring a JIT or AOT compiler to the party.

Java, .NET, Golang are actively used for web development. PHP is popular, especially for small projects, but it definitely did not win, web development is a contested area.

They are also evolving though. I don't know about Ruby and PHP but in Python gradual typing via type annotations really makes projects much easier to maintain and develop these days. While "mypy" (the semi-official type checker tool) still has a long way to go in terms of library support it works really well and helped me to find many issues by analyzing the code, as opposed to running it and finding the issues via tests (or in production).

So I think typing has its merits and languages like Typescript really make development safer and code easier to understand, while still making it possible to write and interface with untyped code if necessary.

I'm not sure this is really true - the subtleties of HTTP are not best handled with dynamic languages, and the actual HTTP API is fairly simple for most web app development. The areas with the most complexity related to the web, itself, are usually do with servers, concurrency, etc - precisely where these languages tend to fall apart.

> This really nails why languages like PHP and Ruby have won out over static typed ...

Real reason is lowering the bar of entry, and that explains why web is horribly broken.

The "bootcamp webshit" meme exists for a reason. That's not gatekeeping - lowering the bar to entry below a certain level leads to drastic decrease in quality.

Depends what one considers application level web development, over here it has been pretty much Java and .NET, with occasional C and C++ written libraries, during the last 20 years.

This is probably true .... but watch out for Node with Typescript. You get that quite iteration, but with a decent amount of type safety most of the time, but with a drop down to the 'any' type for libraries that haven't written type definitions. I also use the existence of type definitions as a guide to how mature the library is :-), so that's a win win.

This is a mistaken view point. Every function you can ever write is bounded by a type, thus whether you use Ruby, PHP, or Rust can be described by a bounded type.

Every time you write logic in your code, your brain is aware that the logic is dealing with a specific type. Writing a type signature on top of that is just additional instructions to the compiler about the type you have already specified in your logic. It is a minor inconvenience.

There are many reasons why Ruby and PHP won out. One of the reasons is many people misunderstand the power and flexibility of types. Once they understand this, they will know there is really no trade off between statically typed and dynamically typed. Statically typed languages are infinitely better and the only downside is a minor inconvenience.

First off, note that there is only one function in the universe that can really take every single type in existence and that function is shown below:

  -- haskell
  identity :: x -> x
  identity x = x

  # python
  def identity(x: Any) -> Any:
      return x

This is the only untyped function in existence. Every other function in the universe must be typed whether it is typed dynamically or statically is irrelevant, either way your code will have to specify the type in logic or in the type signature. You can see this happening in the examples below...

The above example have no logic to specify a type... The minute you start to add any logic to your function immediately your function becomes bounded by a type. Let's say I simply want to add one in my identity function.

  -- haskell
  identity :: Int -> Int
  identity x + 1 = x + 1

  # python
  def identity(x: Int) -> Int:
      return x + 1

The very act of adding even the simplest logic binds your function to a type. In this case it binded my function parameter to an integer. Whether you use PHP or Ruby or Rust there is a type signature that describes all functions.

Let's say I want to do garbage code like write a function that handles an Int or a String? That can be typed as well....

  --haskell
  type IntOrString = Number Int | Characters String
  func :: IntOrString -> IntOrString
  func Number n = n + 1
  func Characters n = n ++ "1"

  #python
  IntOrString = Union[str, int]
  def func(n: IntOrString) -> IntOrString:
      if isinstance(n, int):
         return n + 1
      if isinstance(n, str):
         return n + "1"

Let's say I want to handle every possible JSON api in existence? Well it can be typed as well.

   -- haskell
   type JSON = Number Float | Characters String | Array [JSON] | Map String JSON
   func :: JSON -> JSON
   func Array x = x ++ [1.0]
   func x = x

   -- python
   JSON = Union[float, str, List["JSON"], Dict[str, "JSON"]]
   def func(x: JSON) -> JSON:
     if isinstance(x, list):
        return x + [1.0]
     else:
        return x 

  

There really isn't any additional flexibility afforded to you by a dynamically typed language other than the slight overhead of translating the types you already specified dynamically into types that are specified statically.

One caveat to note here (and this is specific to haskell) is lack of interfaces specific to record types. I cannot specify a type that represents every single record that contains at least a property named x with a type of int.

this was historically true, but I suspect in the age of the evergreen browser this argument has been seriously dented (but not invalidated)

> with high confidence that it will work and last a long time

And we need more of our software to be like that. Now if we could just do something about the constant pressure to compromise.

>>But if you're under pressure to build lots of small, partially documented, constantly changing parts every day, you might be better off using more flexible equipment and materials (balsa wood, bailing wire, masking tape, etc.) to get the job done, even if the result will be messier and more prone to breaking.

Python & Deno/Node fit the bill for the latter category. Would you consider Julia in the former or latter category for ML use-cases?

> JavaScript is cheaper to get started but becomes way more expensive to maintain.

I think this is assumption is a bit too broad. There is another side of this:

In JS you write less code than in Rust and there is less explicit coupling in a dynamic codebase. So changes tend to be smaller and faster as well.

For example if you pass a top-level data-structure X through A, B... and C but only C cares about some part Z. Then you change how Z is produced in A and consumed in C.

If you are dynamic you just do exactly that, which is actually just fine. In a static language you have to change all the B's. Or you take the time and write a sensible abstraction over Z or X so in the future you don't have to change the B's anymore, which is better, but ultimately less readable and more complex.

Stuff that is well understood and specified in advance suits a language like Rust better. You get all these runtime guarantees and performance. You get all this expressive (but explicit!) power to fine-tune abstractions and performance. It's great.

But the closer you get to a UI (especially GUI) and non-technical, direct(!) users, the more dynamic you want to be. Because in this context you are more of a human to computer translator: requirements get discovered via iterations, interactions need to be tested and evolve etc.

You can get that kind of reliability on the front end with Elm, Purescript etc but investing in such niche languages is obviously a nuanced decision.

You're referring to Rust's static type system. What do you make of TypeScript?

The short answer is that because async is not done yet in Rust.

The long answer probably includes GATs (generic associated types), and the even longer answer starts with the amazing work that Nico et al. does to reinvent the internals of the Rust type checker. (Basically - if I remember correctly - the compiler team is currently refactoring big parts of rustc, to librarify the type checker, and replace it with a PROLOG-ish library called "chalk", which is able to prove more things, so it allows better handling of GATs, so it allows better handling of async, where you get "impl Future<Output = T>"-s everywhere.

But also somewhere there is that the ergonomics of async/.await are still not very much in progress too. With better error messages people will be able to forego Box<>-ing and figure out what to use instead, and only heap allocate where they must.

It's possible to write low-level async code with hand rolled-polled Futures, and push/manage as much stuff on the stack as possible. But ... that takes time, and performance is already "good enough". (And/or probably there are bigger gains in performance in other areas, such as scheduling.)

And, finally, boxing helps with compile times. (Because it's basically trivial for the compile to prove that a heap allocated simple trait object behaves well compared to a stack allocated concrete, but usually highly complex (plus unnameable) type.)

As a complete noob to rust, I found attempting to manage a memory pool that is handed out per request to cause all kinds of borrow checking headaches.

My bet is people choose to allocate heavily rather than figure out how to share memory correctly with Rust. I need to learn more rust to get a hang of it so I don't allocate so much.

Are there any rust folks who have a great "list of memory management models for rust"?

I often write my code to allocate at first just to get a feel for the API and business logic and then go through it later to remove them. Given that all of those frameworks are still fairly new it wouldn't shock me to hear that that's the case.

I'd be hard pressed if a backend in Rust gives the same perf as Kotlin/F#. Especially if you write the Rust with an async stack you will likely come out significantly faster than the other options: small binaries, short startup time, less memory usage, more throughput, slightly shorter request cycles, ...

The only place that the langs you mention probably win is: learning curve (F# maybe not so much) a.k.a. getting language illiterate people up to speed, and compile times.

Rust never has to run a garbage collector, because it already figured out the lifetimes of all the values in your program statically, with relatively minor help from the programmer. This may make your code faster or more likely to be correct than code written in some of those languages.

I wish speed mattered more, but JavaScript on Nodejs is performant enough for 95% of websites out there. Most websites are in the long tail, and never need to handle more than about 10 requests per second. For most websites, team velocity matters more than the AWS bill.

A clean static rendering system with caching, built on top of react / svelte / whatever performs well enough for almost everyone. And every year cpu costs drop, V8 gets faster and JS libraries get a little bit more mature.

I love rust, but I don’t see it displacing nodejs any time soon. Maybe when websites can be 100% wasm and the rust web framework ecosystem matures some more. Fingers crossed, but I’m not holding my breath.

Yep! You found a really great open road to drive Rust. I'm jealous :D. If I had an app with as interesting requirements, I'd certainly consider your approach

It would be even more enjoyable if the text was black, had to use reader mode.

Yeah, hashing in WASM seems to be fine in terms of speed, though 60x faster does still sound surprising to me. Hashes with 32 bit words (e.g. sha256) can be optimized fairly well in javascript due to the SMI optimization in engines like v8. I should play around with hashing more.

I was in particular benchmarking ECC, which is much harder to optimize in JS (and in general).

Code is here:

JS: https://github.com/bcoin-org/bcrypto/tree/master/lib/js

C: https://github.com/bcoin-org/libtorsion

To benchmark:

    $ git clone https://github.com/bcoin-org/bcrypto
    $ cd bcrypto
    $ npm install
    $ node bench/ec.js -f 'secp256k1 verify' -B js

    $ git clone https://github.com/bcoin-org/libtorsion
    $ cd libtorsion
    $ cmake . && make
    $ ./torsion_bench
    $ make -f Makefile.wasi SDK=/path/to/wasi-sdk
    $ ./scripts/run-wasi.sh torsion_bench.wasm ecdsa

I think he doesn't complain at all about WASM speed vs JS.

He wants WASM to be closer to C performance. I.e. to move further along this line:

    |JS|========>|WASM|=========>=========>========>|C|

I am writing an app that needs worker threads both on the backend and also on the frontend (because of some heavy processing of large amounts of "objects") and my experience with TS so far is very poor. JS runtimes are just not suitable for heavy concurrent/parallel processing. Serialization/deserialization overhead between threads is probably (much) worse than it would be if the worker threads were in Rust.

It's not a matter of speed here. It's a matter of enabling certain types of programs which are borderline impossible with pure JS runtimes.

So I will probably move most of the logic to Rust

I think the point is only certain use cases (usually related to number crunching like crypto, but undoubtedly games too) may see substantial improvements, they still aren't close to "native" speed, and nearly all other use cases won't see much if any benefit, especially compared to the additional complexity of another language, compiling to was, etc.

Plus things like competitive games and what I'll call "pretty" games have to squeeze out as much performance as possible, and no hitching is acceptable to competitive games, which IMO means WASM is still a no-go for those types of games(although games that don't have this requirement undoubtedly benefit)

No, but I've been meaning to test this. I did notice it was available in node.js with --experimental-wasm-simd. I hope this proves me wrong about wasm, but I'll have to try it.

No. I've just been building with the WASI SDK and running the resulting binary with a small node.js wrapper script. So, I've only tested v8's WASM implementation so far.

Does firefox have a headless mode, a standalone implementation, or some CLI tool I can use to run a WASM binary? Running stuff in the browser is cumbersome.

> each call between WASM and JS has a hefty cost of about 750ns

Why is this the case? Can we expect it to go away as browsers mature?

I agree it still is signficant, but this is not how wasm is being touted. Look at wikipedia: https://en.wikipedia.org/wiki/WebAssembly#History

They even say asm.js is supposed to be "near-native code execution speeds". In my experience, it is no where close to native speed. People should avoid this kind of deceptive marketing.

In some ways it should be faster because it isn't garbage-collected. But I agree that would be a much better benchmark for what should be possible.

Yes, but AI search algorithms like MCTS are slow in general. Even with C, it will be very slow when you want the AI to be smart and consider many actions. IMO, you should train using python libs like [1] and move it to the browser with something like [2] OR run AI in the server. YES definitely writing an AI lib for the browser is a great goal, and as a programmer, it is super interesting. Still, it is tough, and time-to-market is much more crucial, as the entire codebase will change once it will interact with actual people.

[1] https://github.com/datamllab/rlcard

[2] https://onnx.ai/

Please ignore him whole hearty.

Some people want to write profitable apps in the shortest amount of time possible, while others want to advance the state of the art in technology.

IMO we always need more people in the second group. And sometimes, you can hit the jackpot and do both things at the same time!

For a lot of code, if you write JS like you write C (avoid allocations by avoiding the creation of objects, arrays or closures) you should get very comparable performance i.e. within 30% to 50% of C performance

I don't know about JS being slow, while working on https://curvefever.pro it was not too hard to make the game run at 4k, 60FPS for a 6 player multi-player game that renders dynamic geometry with collisions which changes multiple times per tick.

JS is pretty fast if you use TypedArrays, are careful with WebGL calls and pool objects (reduce memory allocations).

You don't have to depend on badly-written untyped third-party libraries, just because there are a lot of them out there. Many projects and companies will avoid doing so. This is especially reasonable if your comparison is switching to a language like Rust; there are probably fewer third-party libraries available in Rust overall than there are libraries with accurate TypeScript definitions available.

Not sure if this is a place to ask this but if someone does not have experience working with Javascript, they might have trouble reasoning about this code:

https://codesandbox.io/s/is849

edit: complete code

```typescript

class Person { id: number; name: string; yearOfBirth: number;

    constructor(id: number, name: string, yearOfBirth: number) {
        this.id  = id;
        this.name = name;
        if (yearOfBirth < 1900 || yearOfBirth > 2020) {
            throw new Error("I don't understand you. Go back to your time machine.");
        } else {
            this.yearOfBirth = yearOfBirth;
        }
    }

    getAge(): number {
        const currentDate: number = new Date().getUTCFullYear();
        return currentDate - this.yearOfBirth;
    }

}

class Dog { id: number; name: string; yearOfBirth: number;

    constructor(id: number, name: string, yearOfBirth: number) {
        this.id  = id;
        this.name = name;
        if (yearOfBirth < 1947 || yearOfBirth > 2020) {
            throw new Error("I don't understand you. Go back to your time machine.");
        } else {
            this.yearOfBirth = yearOfBirth;
        }
    }

    getAge(): number {
        const currentDate: number = new Date().getUTCFullYear();
        return (currentDate - this.yearOfBirth) * 7;
    }

}

const buzz: Person = new Person(1, `Buzz`, 1987);

const airbud: Dog = buzz;

console.log(`Buzz is ${buzz.getAge()} years old.`);

console.log(`Airbud is ${airbud.getAge()} years old in human years.`);

```

I'm a big Rust fan too. I have experience in all of the languages you've mentioned, and I'm most productive in Rust as well.

It's funny you mention enums, there was just another thread last week where I brought up how crazy it is that sum types (Rust enums) and pattern matching have been around since the 70s but have largely been limited to the FP languages. After extensively using Rust for ~3 years now, I don't ever want to use a language without sum types - you can write incredibly expressive and concise code with them.

The other major productivity boost for me is the ability to compose and chain Iterators and mix those with collection types.

I think a lot of the best the best things in Rust don't really have anything to do with low level programming per-se. And I find that for most applications, even with all of the extra goodness, the lack of a GC totally craters productivity. Its not because I'm fighting the borrow checker -- I got the hang of it pretty quick. But it means that every API is complicated by the need to think about lifetimes and ownership, having to think about different types of smart pointer, etc. It means you have to manage all of these silly little details which for most applications are pretty irrelevant.

This isn't a criticism of Rust; it's specifically designed for applications where those things do matter. But for the overwhelming majority of apps they don't, and I'd reach for a different tool.

I've found that once I get into a rhythm and I've been working on something in Rust for a bit, it doesn't feel that hard to deal with all that. And a few times I've thought to myself "hey maybe the GC isn't actually buying you all that much?" But then I go back to a GC'd language and watch just how much faster stuff gets done. It's not even close. I think it's one of these things where your brain doesn't notice the time that goes by when you're doing what is essentially mindless busywork.

Part of this is also having come from doing a fair bit of stuff in Haskell, Elm, and a bit of OCaml; the best "high-level" language features are inspired by that language family (including enums) and so it feels like a better control for the difference a GC makes vs. js and friends. It makes a big difference.

When you're writing synchronous, single-threaded code like, say, a binary file parser or even an HTML scraper with blocking APIs, Rust is 1:1 with high level languages, and usually better.

Where Rust diverges is when you're doing async or multithreaded things with complicate lifetimes.

Getting things right from the start instead of solving them JIT as runtime issues pop up in production over the course of the year is Rust's wheelhouse. But even after using Rust for three years, I sometimes feel like I'm one requirement-change away from a problem I can't solve myself in Rust where I could solve it in a couple hours in another language.

You are probably being downvoted because of this sentence:

> Working in other languages feels like going back to assembly

This is not a preference, it is an exaggeration and an attack on all other languages.

It is also quite ironic given Rust is intended for low level programming.

I have seen this being asked many times in /r/rust and 90% of the answers disagree with you. A common theme is to explore in Python then rewrite in Rust.

There's the hype and there's the reality. Some people don't appreciate the former much and reach for the down arrow...

Rust is nowhere near the productivity of Ruby or Python. If that's the case for you maybe your projects have some peculiarities or it's a personal thing.

This is an important point.

Languages compiled to wasm have an FFI cost, and we will never fully remove it because it just uses different types than Web APIs do. This isn't a Rust problem or a C problem, it's just how wasm is.

Wasm also can't use the JS standard library, and usually ends up shipping some runtime support, like malloc or string handling, which increases download size.

Both of those limitations are why wasm won't make sense for the great majority of web dev work. But wasm shines for "engine" type code, like in this post - pure computation, without lots of links to the outside JS/DOM world.

Best comment in this thread. To the point and factual.

In what ways is Rust more pragmatic than OCaml?

Mind explaining a bit more here why Rust is a particularly good language to compile to wasm? Why does memory safety help here?

Asking out of ignorance!

...Haskell and scala are not part of the ML family. OCAML and F# are languages belonging to the ML family.

They're trying to solve different problems. LLVM is trying to take care of most of the language-independent bits of writing a compiler, while wasm is a format for delivering code to browsers, with an eye towards being a good target for languages like C and making use of the existing JIT compilers in modern browsers.

LLVM as a toolchain provides backends for many target machines, so as a compiler author you can just emit LLVM IR and (mostly)automatically be able to compile for x86, arm, mips, etc... And they have a wasm backend too, so the technologies are complementary -- you can use LLVM to compile to wasm. LLVM will do a fair bit of optimization too. The intent with LLVM is not to provide a portable binary distribution format, but to allow different compiler frontends to all share the same compiler backend logic.

By contrast, with WASM the assumption is that by the time it gets to the browser the ahead-of-time compiler has already done a fair bit of optimization, so what a wasm compiler has to do is much simpler.

WASM is also designed for space efficiency, since the code will be shipped over the network, and safety -- LLVM has a C-like notion of undefined behavior (which the optimizer makes use of), but this would be wildly inappropriate for WASM due to security (and portability) concerns.

There are not comparable afaik. WASM is also more ambitious, along with WASI (system interface) creating a portable final executable (compare to JVM), whereas LLVM is only a set of intermediate language and tools.

When this transition period goes away, LLVM should hopefully compile to WASM binary as a target. The current path described in the video of WASM -> C -> clang -> llvm -> native-binary is a temporary workaround afaik.

GC aside, I've inspected assembly code (.wast files) for top 10 hottest methods in my code, and it was pretty much perfect, Rust and C will probably end up with something similar. However, there was no performance improvements whatsoever, those methods performed similarly to their JS equivalents.

UPD: modern JS engines are extremely capable of optimizing stuff and they can probably come up with machine code similar to what Rust or C will produce given that you keep your code predictable and optimization-friendly.

I'm not the OP but I can confirm in my own project, we found about a 10x performance gap between AssemblyScript and TypeScript. In essence, we're working on a rewrite of DNAVisualization.org[1][2], a serverless web tool for the interactive inspection of raw DNA sequences. We hoped that WASM would give us a performance boost but have been generally disappointed with both the performance and the amount of complexity involved in getting the tooling to work.

We did do a benchmark[3] and, unless we made an error (likely, given that all of us are new to WASM), found that JS was much faster for our simple algorithms. WASM had the approximate performance of our original pure Python implementation[4], so not great.

[1]: https://dnavisualization.org [2]: https://academic.oup.com/nar/article/47/W1/W20/5512090 [3]: https://github.com/Lab41/dnaviz/tree/benchmarks/benchmarks/a.... [4]: https://github.com/Lab41/squiggle

Unfortunately, no, it's a commercial closed-source project. I profiled both JS and WA versions, the hottest methods took basically the same amount of time in both versions, except that WA build additionally spend ~25% of all time in __retain or something like that.

I agree in principle, though in this particular case io-ts does not tend to produce incomprehensible code. Maybe if juniors use it, it would, but it's easy to encapsulate the IO codecs in their own modules where the functional style of io-ts/fp-ts does not leak out to other parts of the code and only types can get reused.

That's not an unreasonable concern but it does mean you're writing code targeting the lowest common denominator. That's not a decision free from negative consequences.

I don't have any statistics, but based on the amount of learning articles, books, etc. out there it seems like Vapor is the dominant Swift Web framework. Kitura looked promising, but IBM has stopped supporting it, so its future is not clear (the last commit to the main branch was in November 2019). Also, the two main Vapor devs are members of the Swift Server Work Group (with the other two being from Apple): https://swift.org/server/

I'm not sure how to answer your question regarding whether Vapor is viable for indie hackers, because I've only been skimming the docs and looking at small examples. But it seems to draw a lot of inspiration from Express.js and/or Ruby's Sinatra library. It doesn't seem to have the up-front complexity of something like Java's Spring Framework, although I understand you can use services and dependency injection if needed. So my first impression is it's easy to get started, but it enables you to refactor to something more complex if your application demands it.

My experience is similar (Milan, Italy.)

If a company is small and/or has to rely on freelancers it goes with dynamically typed languages (PHP, Node, Ruby, Python and Elixir) because that's what the bulk of freelancers use.

If they have many internal developers or use big consultancy firms they go with Java or C#.

Of course there are exceptions (I know a few of them) and my point of view can be biased because I use to see projects and developers of dynamically typed languages.

But I know a few small companies with a code base in Java that had a hard time at finding Java freelancers. Almost all of them are employees, unreachable for them.

This is the fallacy of the grey. Yes, there are nuances and special circumstances, but the overwhelming majority of the time, static typing is simply better. That's one of a small handful of clear consensuses from the last 20-30 years of programming language evolution.

A business decision, what drivel. By that argument, no technical merit of anything ever matters, and yet many things of what’s considered viable in a “business” have changed all the time, some of them because of the push of engineers towards better things.

This is a forum for engineers (not only, I know), who collectively will at least have a large part in steering what languages are considered common in future.

That it can be done doesn't mean is the optimal approach.

I was a diehard fan of dynamic languages for a decade, but eventually I saw the light.

I still use dynamic languages daily, but the bigger the project the more I want proper static typing. None of that mypy stuff, the real deal.

So? There are people who crossed the Atlantic in a kayak, does not mean it's an efficient use of your time. The difference is that the people in the kayak were aware of that.

Python has things that it calls "types" but they're not types according to the standard definition of the word (true types are associated with terms in a language, not with runtime values). And while a runtime error is far better than silent data corruption, it's a poor substitute for a build-time error.

There's another way to deal with it - which is to make crashes not matter. That's actually I would argue even better because you're already coding for robustness.

That's right. For my use-case I decided to just stick with JS for UI stuff (using Svelte). I call into Rust code like a black box to update some state.

I guess the argument was that you can write in JS (well, something that is close to TypeScript which is close to JS anyway) and compile to WASM, therefore the speed argument becomes invalid.