At least in my experience I can read about different architectures all day and sort of understand them, but I only really "get" it once I find a non-toy problem I need to solve and attempt to apply the knowledge. Then you see how it really works and form hard skills which stay with you.
Absolutely this. Wanna learn French? Go to France and live there for a year. Wanna be good at spinning up infrastructure with Terraform? Take an infrastructure job at a company that uses terraform - a start-up if possible, so you get to solve all of the problems. I wanted to learn Terraform and Kubernetes for years, and no amount of books or online courses really helped. Taking a job at a start-up fixed it. In fact, our stack is spookily similar to the one OP posted, Which is validation and also admiration because this person did it solo.
At least in my experience I can read about different architectures all day and sort of understand them, but I only really "get" it once I find a non-toy problem I need to solve and attempt to apply the knowledge. Then you see how it really works and form hard skills which stay with you.