𝗪𝗵𝗲𝗻 𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗜𝘀𝗻'𝘁 𝗙𝗮𝘀𝘁 𝗘𝗻𝗼𝘂𝗴𝗵

𝗪𝗵𝗲𝗻 𝗝𝗮𝘃𝗮𝗦𝗰𝗿𝗶𝗽𝘁 𝗜𝘀𝗻'𝘁 𝗙𝗮𝘀𝘁 𝗘𝗻𝗼𝘂𝗴𝗵

500 requests per second. One minute. Node.js failed. 15.5% of requests errored. Latency hit 3,318 ms.

Switch to a Rust addon. Same server. Same load. Latency dropped to 660 ms. Zero errors. It used less memory.

Bun is faster than Node for JS. It had zero errors. It is 1.8x faster than Node.

The numbers:

• Node JS: 3,318 ms
• Node Rust: 660 ms
• Bun JS: 1,845 ms
• Bun Rust: 642 ms

Rust wins on math. It optimizes loops. It has no garbage collection pauses.

WASM works for the browser. It is 2.2x faster than browser JS.

When to switch:

• Use Rust for CPU heavy work.
• Use Bun for an easy JS speedup.
• Use WASM for browser data analysis.

Rust has a cost. The boundary between JS and Rust adds overhead. This makes Rust slower for small datasets. Rust wins when your data is large.

Do not use Rust for I/O. Use it for math, parsing, and encryption.

Source: https://dev.to/boris9027/when-javascript-isnt-fast-enough-3ia2