Ask HN: What advice would you give an experienced developer to keep improving?

I'm a software developer with over a decade of experience, but I don't feel like a senior developer. I've worked with a variety of languages: C#, Python, C++, and JavaScript mostly. One regret I have is not having enough opportunities to learn from developers more senior than I. I've worked with a few very intelligent developers, but for reasons unspecified, I wasn't given the opportunity to learn much from their experiences.

What would you recommend doing to improve development skills both to be a better employee/developer and to prepare oneself for future interviews? Focus on learning your current languages in greater depth? Learning algorithms and data structures? Other things?