I think the decision to go deep or learn something new depends on what direction you decide to take your career. If you want to go to a Java company for your next job, then by all means study Java deeper. But if you want to explore companies that use Ruby or Python, then you should study those languages.
If I were in your situation, I'll study other programming languages so I can widen the net on the companies that I can do interviews with.
Senior backend developer mainly focus on Java 8 + Spring framework but open to learn new languages. Follower of agile methodologies and user of Linux OS.
I think the decision to go deep or learn something new depends on what direction you decide to take your career. If you want to go to a Java company for your next job, then by all means study Java deeper. But if you want to explore companies that use Ruby or Python, then you should study those languages.
If I were in your situation, I'll study other programming languages so I can widen the net on the companies that I can do interviews with.
That’s a good point. I can increase the number of companies to apply. I will consider it, thanks!