Ask HN: What technologies did you learn in 2019?

It would be very interesting to see what people around the world have been learning in 2019. Any new technologies? Maybe investing more time to deepen the understanding of previously known tech?

As for myself, this year I discovered a programming language that suits my needs perfectly - Clojure/Script. Unfortunately, I don't get to use it professionally (yet), however I use it for my own projects with great joy. Using one programming language across the whole stack, while leveraging robustness of JVM on the back-end and vastness JS on the front-end is immensely empowering!

Previous year's thread (2018): https://news.ycombinator.com/item?id=18745763