Currently reading this and loving it so far. Any recs for more technical introductions?

I also just finished Thinking in Systems and really liked it. I think Feedback Control for Computer Systems[0] is a bit more on the side of a working software engineer (python2 though). Probabilistic Robotics[1] is also an technical approach on control and feedback.

[0]: https://www.amazon.com/Feedback-Control-Computer-Systems-Int...

[1]: https://www.amazon.com/Probabilistic-Robotics-INTELLIGENT-RO...

Modern Control Engineering, by Katsuhiko Ogata, I guess.