For most Django apps, indeed most webapps, the bottleneck is the database. The biggest gains usually come from reducing the number of queries used, and adding database indexes. django-debug-toolbar helps a lot here. After that, caching and de-normalization also help reduce database queries.

But what if your app is CPU bound? How do you find out where it’s spending it’s time? It’s easy with the runprofileserver from django-extensions – here’s how: