YouTube and InfoQ are free and have lots of great content.

.NET is probably lacking good content. Yet many things from Java are directly applicable.

E.g. on benchmarking & performance, there are true gems on InfoQ by Gil Tene, Martin Thompson, et al. I would pay for that content after watching it. A problem with paid courses is that payment goes first before evaluation. Maybe both sides do not care in cases such as corporate spend on continuous education...