Super interesting proposal from David who is working on the wild linker. Sort of inverting the compilation process to drive codegen by what is actually needed, as opposed to compiling everything then throwing away what you don't need later.
The duplicate function checker tool is nifty too, 9% of my release build is duplicate functions. As mentioned in the article there are ways to bring this down if you can accept the trade offs.
https://github.com/davidlattimore/wild
https://github.com/davidlattimore/duplicate-function-checker
