I would go to cloud providers, which can offer me managed rabbitmq, kafka or mongodb

Certainly, I wouldn't get any vendor-specific services like Lambda or SNS (in this example)

The Lambda functions will just be running your business logic code. Only specific part Lambda provides is the glue. Which is easy to replace with any other cloud or self hosted alternative.

The the end of the day, the real reason I went with Lambda to build this is that when I started, I didn't know anything about spinning up a server, building a storage array, or serving an web request. But what I did know was how to write a Python script to extract weather data from a file. The really cool thing about some of these cloud tools is that they let me ignore all of those (very difficult) problems and just focus on the data

Where is your lamda_handler defined? I searched your repos but could not find it.

Exactly what the cloud is best used for imho. You can focus on your core problems and still shift to a different solution later on when that becomes more effective cost wise.

But still, when I first started in AWS we had lift and shift'ed most of our platform onto AWS and when it came to adding new features I first looked at Lambda instead of building out on the existing platform. The speed at which I could setup the feature and start measuring and iterating on it was so much better compared to doing it on our existing platform. Even though that was pretty ironed out and fully automated.