Why is Turbopack written in Rust?

Turbopack is written in Rust, because this language combines high speed, safety, and predictability, which JavaScript-based tools lack when working with large projects and complex dependency graphs.

---

#Reason 1 - Performance

Rust compiles to machine code and runs significantly faster than JS. For a bundler this is critical, because it:

• parses thousands of files,
• builds a dependency graph,
• performs transformations,
• rebuilds parts of the project during HMR.

Rust makes it possible to perform these tasks several times faster than Node.js.

---

#Reason 2 - Memory safety

Rust guarantees safety at the compiler level: no memory leaks, data races, or crashes from careless resource handling. For a complex build tool this matters, because:

• the build must be stable and predictable,
• errors should be caught at compile time, not at runtime.

---

#Reason 3 - Working with parallelism

Rust scales well on multi-core systems. In a bundler this makes it possible to:

• process files in parallel,
• cache efficiently and incrementally rebuild only the changed modules.

---

#Reason 4 - Webpack's limitations

Webpack is written in JS and hits the speed limits of an interpreted language. Turbopack was created as its "successor", so Rust was a logical choice for solving the performance problem.

---

#Summary

Turbopack is written in Rust because Rust provides maximum speed, safety, and efficient parallelism, making it better suited for the new generation of ultra-fast build tools.