What should you pay attention to when learning the back-end in Java?

Question

Java

At the current time, I have already more or less mastered the development of a backend on .NET Core and I got the idea to see how to make a backend (at least a simple one) for Java.
The question is, what tools, libraries, frameworks can you advise to pay attention to in the first place for writing at least a simple backend in Java?

Answer 1

Learn Spring Boot (Spring Framework). Learn to write both simple and complex projects. There is a separate Spring Cloud ecosystem, etc., which allow you to develop even more complex services.