swc

Building for production takes ~10 minutes, and svelte-check adds another ~10 minutes, making it 20+ minutes total. esbuild, swc, and rspack lack good Svelte support, making workarounds difficult. Build times worsen as projects grow.

TypeScript adds a compilation step to the development workflow that can take seconds or minutes in large projects, slowing down the development cycle. While modern tools like esbuild, swc, and Vite help reduce build times, this overhead remains a consideration for project setup.