JavaScript bundlers and transpilers, often written in JavaScript, lack efficiency, but can be optimized using faster languages like Rust. The article explores using the Rust-based spack bundler with the swc-project to enhance JavaScript build speeds. Swc-project, a collection of Rust-written bundlers and transpilers, is notably faster than Babel and supports transpiling various JavaScript versions including TypeScript, JSX, and TSX. Spack, an alternative to webpack, supports features like dead code elimination and tree shaking, and relies on the swc_bundler crate for asset bundling. It can be configured using .swcrc and spack.config.js files, allowing developers to adapt codes to be compatible with older JavaScript versions for broader browser support. The article emphasizes spack's capability to handle multiple JavaScript entries and its integration with Deno for TypeScript, highlighting it as a promising tool in development environments.