I am not familiar with AWS apis. Probably Java was more suitable for this task then, as it often comes down to how good the documentation and tutorials are for the task and how many people use it. Like you said bad documentation is a big issue.

I can also see how they could struggle with python dependencies, which I guess is the reason why they struggled setting up flask. With a java project you can just nuke everything from scratch and reinstall the correct compatible packages. But with python global dependencies (without env) you cannot get around the issue like that. That makes it harder for beginners. (But for intermediate give me anything but maven please).

Maybe Python flask wasn't't the tool for the task here, but I still think it's overall better and especially faster to use for most things.