I’m a mid-level backend dev, ~3 years YOE. I wanted to seriously start thinking about expanding my skillset and learning new stuff / new technologies outside of my daily tasks. But I’m unsure of how to start, how to decide, what would be most helpful to my career, etc. Any advice?
I found it crazy useful to study old, established, mature technologies, like relational databases, storage, low-level networking stack, optimizing compilers, etc. Much more valuable than learning the fad of the year. For example, consider studying internals of Postgresql if you’re using it.