The article explores techniques to optimize Rust build speeds, highlighting the challenges associated with Rust's slow compilation, particularly for large projects, and introduces sccache as a solution. sccache, a distributed compiler cache, can significantly reduce build times by caching and reusing Rust compilation outputs. The article provides guidance on installing and configuring sccache, integrating it with Cargo, and applying caching in continuous integration (CI) environments. It also discusses potential limitations of sccache, such as network overhead and its effectiveness with incremental compilation. To address these issues, Earthly offers an alternative, lib/rust, which leverages incremental compilation for more efficient caching, making it particularly effective in CI environments. The author encourages exploring lib/rust for further optimization and invites community feedback to enhance the Rust development experience.