I used Docker and Kubernetes to make an extensible microservice based website to host comic books from scratch. I might write more about this in the future, but to summarize, I learned about Java Servlets, extensibility, scaling up and down, load balancing, Kubernetes clustering and nodes, setting up docker files and images, requesting storage resources, messaging between services and authentication of accounts. Sending GET, POST requests, broker services, Google Cloud hosting, secure search queries, saving session data, etc.
I brushed up on topics I already knew like HTML, CSS UI/UX design, SQL and database management. This was for a class on Software Design and Architecture.