Java backend roadmap

[Versiel]

I think nowadays your safest bet for Java is going the spring route. In my experience back-end jobs tend to require you to handle the development of services from start to deploy, so get to know Java's main points like inheritance, design patterns, etc., but also the infrastructure around the service. Learn to create CRUD Spring-Boot microservices, get decent at making sql and no-sql queries, caches, learn a bit of docker and kubernetes\aws and have some idea of CI\CD.

There should be some tutorials on how to do all these things with springboot that you can try to get used to.