i am a hobbyist programmer looking mainly for fun (some cash is not bad tbh) , i have programmed before in VB6 ,c# and some c++. i realize that c/c++ is used heavily in programming operating systems/games...etc.i really like the idea of low level /high performance programming that is why i like c++. the problem is that programming these stuff require massive number of programmers , not something i can do alone.

what interesting and useful stuff a lonely c/c++ programmer can do ?