story
As for the "compilers are special" reasoning, I don't ascribe to it. I suppose because it implies the opposite: something (other than a compiler) is especially suited to run well in a scripting language. But the former doesn't imply the later in reality and so the case should be made independently. The Prisma case is one: you are already dealing with JavaScript objects so it is wise to stay in JavaScript. The old cases I would choose the scripting language (familiarity, speed of adding new features, ability to hire a team quickly) seem to be eroding in the face of LLMs.
WASM is used to generate the query plan, but query execution now happens entirely within TypeScript, whereas under the previous architecture both steps were handled by Rust. So in a very literal sense some of the Rust code is being rewritten in TypeScript.
> Basically, if the majority of your application is already in JavaScript and expects primarily to interact with other code written in JavaScript, it usually doesn't make sense to serialize your data, pass it to another runtime for some processing, then pass the result back.
My point was simply to refute the assertion that once software is written in a low level language, it will never be converted to a higher level language, as if low level languages are necessarily the terminal state for all software, which is what your original comment seemed to be suggesting. This feels like a bit of a "No true Scotsman" argument: https://en.wikipedia.org/wiki/No_true_Scotsman
> As for the "compilers are special" reasoning, I don't ascribe to it.
Compilers (and more specifically lexers and parsers) are special in the sense that they're incredibly well suited for languages with shared memory multithreading. Not every workload fits that profile.
> The old cases I would choose the scripting language (familiarity, speed of adding new features, ability to hire a team quickly) seem to be eroding in the face of LLMs.
I'm not an AI pessimist, but I'm also not an AI maximalist who is convinced that AI will completely eliminate the need for human code authoring and review, and as long as humans are required to write and review code, then those benefits still apply. In fact, one of the stated reasons for the Prisma rewrite was "skillset barriers". "Contributing to the query engine requires a combination of Rust and TypeScript proficiency, reducing the opportunity for community involvement." [1]
[1] https://www.prisma.io/blog/from-rust-to-typescript-a-new-cha...
That is why I am saying your evidence is a red herring. It is a case where a reasonable decision was made to rewrite in JavaScript/TypeScript but it has nothing to do with the merits of the language and everything to do with the environment that the entire system is running in. They even state the Rust code is fast (and undoubtedly faster than the JS version), just not fast enough to justify the IPC cost.
And it in no way applies to the point I am making, where I explicitly question "starting a new project" for example "my default assumption to use JS runtimes on the server". It's closer to a "Well, actually ..." than an attempt to clarify or provide a reasoned response.
The world is changing before our eyes. The coding LLMs we have already are good but the ones in the pipeline are better. The ones coming next year are likely to be even better. It is time to revisit our long held opinions. And in the case of "reads data from a OS socket/file-descriptor and writes data to a OS socket/file-descriptor", which is the case for a significant number of applications including web servers, I'm starting to doubt that choosing a scripting language for that task, as I once advocated, is a good plan given what I am seeing.
First of all, I would argue that software rewrites are a bad proxy metric for language quality in general. Language rewrites don't measure languages purely on a qualitative scale, but rather on a scale of how likely they are to be misused in the wrong problem domain.
Low level languages tend to have a higher barrier to entry, which as a result means they're less likely to be chosen on a whim during the first iteration of a project. This phenomenon is exhibited not just at the macroscopic level of language choice, but often times when determining which data structures and techniques to use within a specific language. I've very seldomly found myself accidentally reaching for a Uint8Array or a WeakRef in JS when a normal array or reference would suffice, and then having to rewrite my code, not because those solutions are superior, but because they're so much less ergonomic that I'm only likely to use them when I'm relatively certain they're required.
This results in obvious selection bias. If you were to survey JS developers and ask how often they've rewritten a normal reference in favor of a WeakRef vs the opposite migration, the results would be skewed because the cost of dereferencing WeakRefs is high enough that you're unlikely to use them hastily. The same is true to a certain extent in regards to language choice. Developers are less likely to spend time appeasing Rust's borrow checker when PHP/Ruby/JS would suffice, so if a scripting language is the best choice for the problem at hand, they're less likely to get it wrong during the first iteration and have to suffer through a massive rewrite (and then post about it on HN). I've seen plenty of examples of competent software developers saying they'd choose a scripting language in lieu of Go/Rust/Zig. Here's the founder of Hashicorp (who built his company on Go, and who's currently building a terminal in Zig), saying he'd choose PHP or Rails for a web server in 2025: https://www.youtube.com/watch?v=YQnz7L6x068&t=1821s
Making technical decisions based on hypothetical technologies that may solve your problems in "a year or so" is a gamble.
> And in the case of "reads data from a OS socket/file-descriptor and writes data to a OS socket/file-descriptor", which is the case for a significant number of applications including web servers, I'm starting to doubt that choosing a scripting language for that task, as I once advocated, is a good plan given what I am seeing.
Arguably Go is a scripting language designed for exactly that purpose.
1. As products mature, they may find useful scenarios involving runtime environments that don’t necessarily match the ones that were in mind back when the foundation was laid. If relevant parts are rewritten in a lower-level language like C or Rust, it becomes possible to reuse them across environments (in embedded land, in Web via WASM, etc.) without duplicate implementations while mostly preserving or even improving performance and unlocking new use cases and interesting integrations.
2. As products mature, they may find use cases that have drastically different performance requirements. TypeScript was not used for truly massive codebases, until it was, and then performance became a big issue.
Starting a product trying to get all of the above from the get go is rarely a good idea: a product that rots and has little adoption due to feature creep and lack of focus (with resulting bugs and/or slow progress) doesn’t stand a chance against a product that runs slower and in fewer environments but, crucially, 1) is released, 2) makes sound design decisions, and 3) functions sufficiently well for the purposes of its audience.
Whether LLMs are involved or not makes no meaningful difference: no matter how good your autocomplete is, other things equal the second instance still wins over the first—it still takes less time to reach the usefulness threshold and start gaining adoption. (And if you are making a religious argument about omniscient entities for which there is no meaningful difference between those two cases, which can instantly develop a bug-free product with infinite flexibility and perfect performance at whatever the level of abstraction required, coming any year, then you should double-check whether if they do arrive anyone would still be using them for this purpose. In a world where I, a hypothetical end user, can get X instantly conjured for me out of thin air by a genie, you, a hypothetical software developer, better have that genie conjure you some money lest your family goes hungry.)
