[kohanz]

We had a dependency limitation where an SDK we relied on only had an x86 release while our software ran (necessarily) as x64. I was quite proud of myself when I wrote (in a relatively short period of time) an IPC-based (memory mapped files) solution to communicate between the two seamlessly (performance mattered, as we were doing real-time imaging). It felt like a problem that some of my co-workers would have just given up on and said "it's not possible". Might not have been the "toughest", but in terms of time/difficulty trade-off, it ranks up there. Perhaps it would be trivial for others.

Of course, the real solution would be to press the dependency provider to release an x64 version, but we were not a priority of theirs.