Although I am a .NET developer as well, I focus on expanding my project management and leadership skills, as well as developing skills in AI/ML.
Rather than bore with all the details of my background, here is what I think:
- You should develop your skills in AI/ML, if only by familiarizing yourself with TensorFlow and CNTK. Even if you are not the expert, you should understand it.
- Consider other languages like Python and R by watching trends using TIOBE (https://www.tiobe.com/tiobe-index/) and PYPL (http://pypl.github.io/PYPL.html).
Somewhat more generally:
- Develop your leadership and management skills, if only to become better developer, even if you don’t aspire to higher rank, and having those skills will make one more hireable developer
- Although the landscape might change, it is unlikely that you could not find a job with .NET skills in 5 to 6 years, but the most important thing is to keep in touch with the changes, developing as needed
- Consider what would put you out of a job, say automation that builds the things you already do and do that. Stay ahead of the wave that is going to crush you, by becoming part of the wave itself.
- Create an online presence via blogs, codeshares, NuGet and GitHub repo’s, contributions to other projects, and career sites. Make recruiters come to you.