Introduction Building a web app relying on database calls with CPython (the standard Python distribution) is pretty easy, but can suffer from performance problems. Python itself isn’t particularly fast, and in 2.x, it’s concurrency story is especially weak. For starters, there’s the dreaded GIL. The GIL prevents us from taking advantage of multi core systems, so even if we use try to use threads we’re missing out on their main performance benefit, which is parallel computation.