Mold 3.0: A Case Study in Extreme Concurrency and Modern Systems Engineering

Mold 3.0 is out, and it is a massive case study in modern systems engineering.

The blisteringly fast linker has been completely rewritten from C++ to Rust. For a tool that operates at the absolute limit of memory bandwidth and concurrency, this is a major architectural shift.

Linkers are brutal to maintain. Shifting to Rust allows the maintainers to keep the raw execution speed of C++ while letting the compiler safely manage complex data races and pointer lifetimes. The result is a highly predictable, rock-solid codebase that does not sacrifice a single nanosecond of performance.

It is a perfect example of moving past language tribalism to choose the right tool for extreme concurrency.

If you want to kill your build times, drop it into your toolchain.