PPallemberg

Is there a course about advanced usage of Docker too?

You definitely can, the principle is still valid. Anyway, Route53 is extremely cheap, less than a dollar for a million queries per month, is very reliable and it integrates very well with the other AWS services, so it's definitely worth the price, IMO. What alternative services where you thinking about?

I like how they took a simple use case and were able to show the key concepts of designing stuff with HA as a priority. I'd have like to see some hints about security too, that would have been a nice addition