Where do the elite assemblers live?
I'm looking for "next level" assembly code, by people who only do assembly, for hobby and for a career for years. Thank you!!
MenuetOS (1) is an operating system where everything is written in assembly including the applications.
1. http://menuetos.net/
Look into the demo scene and their multiple groups and events for hyperoptimised assembly on sometimes exotics platforms.
Alternatively, reverse engineering and vulnerability research is, while less focused on writing assembly and more on understanding it, another area where you'll find competent people.
If you can track down a copy of the IBM XT or AT technical reference manuals, you will find a complete listing of the BIOS. Not only is it a substantial piece of assembly code, but you might even learn a bit about how a PC starts up. Ok, maybe not the latest EFI ones.
Go read @a2_4am's reverse engineering of old Apple ][ copy protection code. The code itself is amazingly tricky and the work to decipher it even more so.
Embedded stuff, where the bytes still count.