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...

Obligatory link to "Probabilistic Robotics" -- generally considered the #1 reference on the subject, written by top roboticists (Thrun, Burgard, and Fox): http://www.amazon.com/Probabilistic-Robotics-Intelligent-Aut...