Fun fact, on the lowest memory available, cold start times are really bad in Python when you have a lot of libraries that need to be imported.

The Lambda runtime is exceedingly slow at that on the 128MB tier. This is in fact the case for Django apps, even in their default state.

Now here's where the fun fact starts: If a function times out during cold start, it hasn't successfully been warmed. That means upon its next trigger, it will coldstart again.

Now lets say you deploy a tiny little function over wsgi. You see in your metrics that it takes an avg of 200ms... now, you're a smart dev, you set its global timeout to 3 seconds down from the default of 30 seconds because you don't want to get billed more than necessary. But as it turns out, the cold start takes on average 10 seconds. Your function now never successfully completes.