not to mention bugs in the micros themselves. I lost a few weeks of my life to one that would corrupt the stack in certain situations in an interrupt. The only way to debug it was with a logic anaylzer on all the memory / data lines / interrupts and decode it into opcodes and see what it was doing in the interrupts. Then when found, get bacck to the manufacturer who eventually gets back and says they already knew about it, but hadn't done and errata for it.... so yeah.... these days I mainly do backend/front end stuff :)