A few configuration issues while we learned which ones performed as described on FreeBSD. It loads python modules BEFORE forking workers, so if you use multiprocessing or anything to create procs it will do it once before the fork, and all post-fork children are left sharing the same pool unless you instantiate it during the first request or a similar approach. These are just things to be aware of, and are not necessarily black marks against its usefulness assuming you are willing to accept a certain cost of learning the features (there are a lot). I'm still using it, but I'm not really convinced that I'm better off than if we had picked gunicorn or similar initially and skipped some headaches.