My concern is that we repeat so often "Python is slow" that we can forget when this is a valid assumption. I've already dealt with people using since the start

My concern is that we repeat so often "Python is slow" that we can forget when this is a valid assumption. I've already dealt with people using since the start of a project a low-level language because "it's faster" (and the project was obviously not CPU-bound). The same goes with explaining a huge latency on connecting to a web service as "you're using Python on the client" Is Python slower than C? In some cases YES. Is Python a slow language? NO, not always. Do I think that titles like "Why Python is slow" are misleading? YES, because are too generic, and give the wrong kind of idea. Speed, as scalability or a lot of other concepts, are WAY more a problem of architecture and design than language. This doesn't mean that languages are irrelevant, but their importance in the achievement (or failure) of those goals is largely overstated. PD: You can replace Python with Ruby or JavaScript.