Depending on the language you use VScode might not be any more performant because it probably uses the same LSP on top of electron instead of elisp. I write Rust/C++ on a sizable project and since everyone depends on rust-analyzer* all IDEs are just unbearably slow and mostly useless in language integration beyond basic refactors and click to go to definition.
* except RustRover but that comes with its own set of issues
Nothing special or too sophisticated. On the one hand I use Just (a command runner) to standardize specific build and test commands that call cargo with various flags. Here is a simple example from one of my repos: https://github.com/deepmesa/deepmesa-rs/blob/mainline/justfi...
Then I have a bunch of elisp code that calls just and / or generates boilerplate code right in the buffer - M-x new-macro or M-x run-test (asks for a test to run) etc. I keep writing more elisp as I go along and add specific key bindings to specific things and now its too hard to move away from it all.
* except RustRover but that comes with its own set of issues