Browsers are now able to stream files from disk so you can create a high performance tool that'll read locally, do [x] with it and present the results, all without any network overhead.

I have a SaaS project where the backend is in JS. I also have some data processing to do with large file (several TB). Doing it is in JS is more convenient as I can reuse code from the backend, and it is also the language I know best.

Performance-wise, I get about half the throughput I had with the same processsing done it rust, which doesn't change anything for my use-case.

However that's not really relevant to the context of the post as I'm using node.js streams which are both saner and fast. I'm guessing that the post is relevant to people using server-side runtimes that only implement web streams.

You don't always have a choice on where you deliver your software. It'd be nice to have good tools wherever you are forced to work.

Browsers

Since when are browsers themselves built in JavaScript? Mainstream, fast ones?

Clarification - in the past when I've written high performance data tools in JS, it was almost entirely to support the use case of needing it to run in a browser. Otherwise, there are indeed more suitable environments available.

To your question, I was about to point out Firefox[1], but realized you clarified 'mainstream'[2]...

[1] https://briangrinstead.com/blog/firefox-webcomponents

[2] https://gs.statcounter.com/browser-market-share