PyPy is definitely used behind the scenes in many places. IMHO you don't often hear about it because if you're ready to take the performance hit that comes with

PyPy is definitely used behind the scenes in many places. IMHO you don't often hear about it because if you're ready to take the performance hit that comes with python you're probably not trying to squeeze the best out of it all the time. There was also the lack of compatibility with existing packages, a big issue in the past, but nowdays it's pretty rare. You can often just run your program into both and measure if using pypy makes sense for your task. Frequently the free speedup is very welcome, especially for long or repeating jobs. Even when used opportunistically like this PyPy is still tremendously useful.