TypeScript's Go port runs 10x faster; Cloudflare's Rust proxy uses under half the CPU

01The line: a quarter of Firefox's native code is now Rust

Firefox is the longest public record of a large codebase changing language piece by piece rather than in one rewrite. Rust was 8.7% of its Rust, C and C++ lines at the first release of 2018 and 19.0% by 2021, then flat for three years. Firefox 158, released on 7 October, carried 6.24 million lines of Rust: 26.1%.¹⁵

02What drives it: speed the teams measured, and reasons that disagree

TypeScript, to Go. Microsoft announced the port in March 2025 with a first benchmark: VS Code’s 1.5 million lines compiled in 7.5 seconds instead of 77.8.² TypeScript 7.0 shipped on 8 July 2026 with “speedups between 8x and 12x on full builds” and lower memory use on all five codebases Microsoft published, by 6% to 26%.¹ The 7.1 beta of 20 October ran a further 1.2x to 1.9x faster than 7.0 on Microsoft’s five test codebases, with 15.8% to 49.6% less memory.³

Cloudflare’s proxy, to Rust. FL1, the software that handles every request, was NGINX (written in C) with LuaJIT. Its Rust replacement, FL2, responds 10 ms faster at the median, “a 25% performance boost” on third-party tests, and uses “less than half the CPU of FL1, and much less than half the memory”. Cloudflare gives the main reason as design, not language: “The biggest reason for this is simply that FL2 performs less work,” and FL1 spent time converting data between languages.⁵ On 18 September it reclaimed more than 100 TB of RAM in a service already written in Rust by changing an algorithm, and closed: “You might not be able to solve all your problems with Rust, but math is universal.”⁶

Python tools, to Rust. Astral’s Ruff lints the CPython codebase from scratch in 0.29 seconds; Flake8 takes 12.26 and Pylint more than 60, on the project’s own chart.¹¹ Its installer, uv, was “8-10x faster than pip and pip-tools without caching, and 80-115x faster when running with a warm cache” at launch in February 2024,¹² and installs one test project’s dependencies from a warm cache in 0.06 seconds against 4.63 for pip-sync.¹³ In March 2026 Astral agreed to join OpenAI’s Codex team and said it would keep its tools open source.¹⁴

Discord, from Go to Rust (2020). Its “Read States” service showed latency spikes “roughly every 2 minutes” on Go 1.9.2; in Rust, “Latency, CPU, and memory were all better.” The post gives its numbers only as charts.⁹

Each team’s stated reason for its language, in its own words:

• Cloudflare, Rust (2025): “Built in Rust, it eliminates entire classes of bugs that plagued our Nginx/LuaJIT-based FL1, like memory safety issues and data races, while delivering C-level performance.”⁵
• TypeScript team, Go (2025): “Idiomatic Go strongly resembles the existing coding patterns of the TypeScript codebase.” On garbage collection: “We don’t have any strong latency constraints that would suffer from GC pauses/slowdowns.” And: “many languages would be suitable in a ground-up rewrite situation.”⁴
• Discord, Rust (2020): “the spikes were due to core Go features: its memory model and garbage collector (GC).” Also: “we don’t think you should rewrite everything in rust just because.”⁹
• Astral, Rust (2022): “Python tooling could be rewritten in more performant languages.”¹⁰
• Cloudflare, tsrs, Rust (20 October 2026): “it’s not just about speed”; “When you compile a Go program to Wasm, you have to compile Go’s garbage collector along with it.”⁷

03What it means for a buyer

Faster tools are the nearest gain, on your code. Every figure above is a benchmark on codebases and machines the team chose. uv’s benchmark page warns that results “may vary dramatically across different operating systems and filesystems”,¹³ and Cloudflare’s tsrs post notes that some published TypeScript-port claims used larger machines and non-default options.⁷ The useful number is your own build or test run, before and after.

Fewer memory bugs is a design claim; the teams name its limits. Cloudflare says Rust removes whole classes of bug, and in the same post: “It’s easy to write code in Rust, which causes memory corruption.”⁵ On 18 November 2025 a configuration file grew past a fixed limit; FL2’s Rust code “panicked” and customers on it got HTTP 5xx errors, while customers still on the old FL saw no errors and all their traffic was given a bot score of zero.⁸ Memory safety did not prevent that outage, and the older code returned wrong results rather than errors.

Migration has a cost the teams recorded. TypeScript 7.0 shipped without a stable programmatic API, so “Projects using Vue, MDX, Astro, Svelte, and others will need to continue using TypeScript 6.0 for now”;¹ the 7.1 beta adds the API and a way for those tools to plug in.³ tsrs still prints some diagnostics in a different order from TypeScript.⁷