Hi!

I noticed that in the Cargo.toml file Link-Time Optimization (LTO) for the Rust part of the project is not enabled. I suggest switching it on since it will reduce the binary size (always a good thing to have) and will likely improve the project's performance.

I suggest enabling LTO only for the Release builds so as not to sacrifice the developers' experience while working on the project since LTO consumes an additional amount of time to finish the compilation routine. If you think that a regular Release build should not be affected by such a change as well, then I suggest adding an additional release-lto profile where additionally to regular release optimizations LTO also will be added. Such a change simplifies life for maintainers and others interested in the project persons who want to build the most performant version of the application. Using ThinLTO also should help).

Additionally to LTO, I can suggest evaluating more advanced optimizations like Profile-Guided Optimization (PGO) and Post-Link Optimization (PLO). I have a lot of information (including a lot of benchmarks for many projects, including many databases!) in my repository: https://github.com/zamazan4ik/awesome-pgo . I expect measurable improvements from enabling PGO for Feldera. You can start to play with PGO with https://github.com/Kobzol/cargo-pgo

Thank you.