Cutting down Rust compile times from 30 to 2 minutes with one thousand crates

Rust is fast at runtime — but not so much at compile time. That’s hardly news to anyone who's worked on a serious Rust codebase. There's a whole genre of blog posts dedicated to shaving seconds off cargo build . At Feldera, we let users write SQL to define tables and views. Under the hood, we compile that SQL into Rust code — which is then compiled with rustc to a single binary that incrementally maintains all views as new data streams into tables. We’ve already pulled a lot of tricks in the past to speed up compilation: type erasure, aggressive code deduplication, limiting codegen lines. And that got us quite far. However, recently we started on-boarding a new, large enterprise client with fairly complicated SQL. They wrote many, very large programs with Feldera. For example, one of them was 8562 lines of SQL code that eventually is translated to ~100k lines of Rust code by the Feldera SQL-to-Rust compiler. To be clear, this isn’t some massive monolith we’re compiling. We’re talkin ... Read full article.