Python
I have written countless projects in python at this point and I feel like I'm at a stage in my python career that I have it down. I can do basically anything with it so long as there is some documentation for me to follow. I have created multiple backends and REST APIs in it, worked with databases, scientific mathematics, and much more. I am currently diving into the world of AI and Machine Learning as I feel that's where a lot of cool stuff is going to be emerging from in the next 10 years.