---
title: "Speeding up the JavaScript ecosystem - oxlint and oxfmt"
url: https://daily.dev/posts/speeding-up-the-javascript-ecosystem---oxlint-and-oxfmt-ekt0txiij
source_url: https://marvinh.dev/blog/speeding-up-javascript-ecosystem-part-13
type: article
source: "Marvin Hagemeister"
published: 2026-05-17T21:09:57.274Z
updated: 2026-05-17T21:10:26.468Z
tags: ["javascript", "performance", "rust"]
reading_time: 6
upvotes: 43
comments: 5
language: en
---

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# Speeding up the JavaScript ecosystem - oxlint and oxfmt

**[Marvin Hagemeister](https://daily.dev/sources/marvinh)** · 6 min read · 43 upvotes · 5 comments

## Summary

A deep-dive into a performance bottleneck discovered in oxlint and oxfmt when run on codebases with many directories. The root cause was excessive syscalls during config file discovery: each `.is_file()` call triggers a full kernel context switch, and with 150k sequential calls across 50k directories, this created massive latency. The fix replaces individual `is_file()` checks with `readdir`-based traversal, which returns filenames and file types for free without extra syscalls. Additionally, the two-phase approach (config discovery then linting) was fused into a single traversal pass. The result is a ~50% speedup (6.1s → 2.8s) for large projects with many directories.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://marvinh.dev/blog/speeding-up-javascript-ecosystem-part-13>

## Community discussion

Top comments from developers on daily.dev.

**@yaireo** · 10 upvotes

> I'll just say many already have been using [Biome](https://biomejs.dev/) for some time now and are very pleased. It's a single mature tool.

**@enzoalbornoz** · 3 upvotes

> I'm still waiting for Vue support. I'm eager to use it

**@mheob** · 2 upvotes

> We switched to `oxlint` and `oxfmt` a few weeks ago. And it was a great decision. We're saving about 60% of the time we used to spend on linting and formatting.

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---

Tags: [#javascript](https://daily.dev/tags/javascript), [#performance](https://daily.dev/tags/performance), [#rust](https://daily.dev/tags/rust)

[View this post on daily.dev](https://daily.dev/posts/speeding-up-the-javascript-ecosystem---oxlint-and-oxfmt-ekt0txiij)