If you intend to build Java based backend for your website or application, this might be the right place.While spring provides many on the go services (Security, DataBase APIs, Cloud, etc) - the core lies in having depth about these and being able to tweak them based on your requirements. 

Coming from 3+ years of experience in Software and algorithms design background, my prime focus has always been making efficient/flawless application backend logic - keeping the program extensible to possible future requirements you might have. 

Being naturally curious, I am  usually open to flexible requirements and proper all round discussions about them before hand - provided I like the project, too.