20 years as a professional firmware engineer for 8/16/32-bit MCUs (AVR, PIC, ARM Cortex M). I'm an expert C (and ASM for a few architectures) programmer for bare-metal platforms and okay-ish whenever a real OS is involved.

I tend to be stuck in Windows-land, because the corporate world of embedded software demands it, but I've dabbled in Classic MacOS, OS X, Linux, and Windows programming. I usually write in C even when it's obviously the wrong choice. Working on some Win32 GUI stuff right now, in C of course. But I can get pretty fancy with some batch (.cmd) scripting.