# Bun's migration from Zig to Rust reduced the estimated timeline from 1-2 years to 11 days

DevFeed: [Bun's migration from Zig to Rust reduced the estimated timeline from 1-2 years to 11 days](<https://devfeed.tech/articles/the-pulse-what-can-we-learn-from-bun-s-rapid-rust-rewrite-with-ai-40930.md>)

Original publisher: [Read original article](<https://blog.pragmaticengineer.com/the-pulse-what-can-we-learn-from-buns-rapid-rust-rewrite-with-ai/>)

Author: Ivan Klaric

Published: 2026-07-16T16:50:20Z

Content type: opinion

Language: en

Sources: [The Pragmatic Engineer](<https://devfeed.tech/sources/the-pragmatic-engineer-2.md>)

Topics: [Bun](<https://devfeed.tech/topics/bun.md>), [migration](<https://devfeed.tech/topics/migration.md>), [Rust](<https://devfeed.tech/topics/rust.md>), [Zig](<https://devfeed.tech/topics/zig.md>), [Fable](<https://devfeed.tech/topics/fable.md>), [Memory Leaks](<https://devfeed.tech/topics/memory-leaks.md>)

Tags: [bun](<https://devfeed.tech/tags/bun.md>), [fable](<https://devfeed.tech/tags/fable.md>), [memory-leaks](<https://devfeed.tech/tags/memory-leaks.md>), [migration](<https://devfeed.tech/tags/migration.md>), [rust](<https://devfeed.tech/tags/rust.md>), [zig](<https://devfeed.tech/tags/zig.md>)

## AI overview

The article examines Bun's rewrite from Zig to Rust, focusing on memory-safety problems and the migration approach. It reports that the migration timeline was shortened from an estimated 1-2 years to 11 days, while emphasizing that thorough testing was required.

## Source excerpt

To a sceptic, spending $165K to migrate Bun from Zig to Rust sounds very expensive. But to a realist, shortening a 1-2 year migration down to 11 days opens amazing new opportunities for devs. However, a thoroughly-tested project is required to pull it off.