Am I missing something - this was really a such a problem that it was a factor in switching languages?
Perhaps I am being uncharitable. I note with interest they say, "However, we had a strong aversion to using Java itself", but don't explain why they had that aversion, or whether it was based on anything but the fact that Java isn't trendy.
It didn't seem interesting to rehash why we didn't want Java's verbosity in a small team.
That's after you figure out which 50 different *-dev libs you have to sudo apt-get install, in a tedious process of trial-and-error, ./configure, make, and error.
With Clojure this is a non-issue. lein will download what dependencies you need. And they're all already compiled into .jars. This is a benefit of the JVM infrastructure, but we're comparing Python here, so.
And of course you can upgrade the EC2 instance, but an annoying and time-consuming process, since you're not in control of the AWS account yourself, and the entire issue doesn't exist if you're using Clojure.
If you have to do it very often, I've had good success with keeping compiled python wheels around.
There are a lot of things that are mostly painless if you're deploying and supporting a single instance that become nightmares at the scale hundreds or thousands of installations you don't control.
Installing Oracle client is even worse though ;)
(author of the post)