Here are some that I've been following why working on my newsletter (https://weeklyrobotics.com/). These will be mostly robotics oriented, and some of them might be inactive:

* [Robots&Chisel](http://www.robotandchisel.com/blog/) - a blog by Michael Ferguson, he did a very nice series of posts on restoring a UBR-1 robot and implementing ROS-2 on it

* [Mike Isted](https://mikeisted.wordpress.com/) - at one point Mike was writing quite many blog posts on making drones, including some offboard control and autonomy

* [The Interrupt](https://interrupt.memfault.com/) - in-depth blog about embedded programming. Really like their monthly "What we've been reading..." series

* [Electron Dust](https://www.electrondust.com/) - inactive, but a really cool series of blog post on making a ball bouncing robot

* [Casey Handmer blog](https://caseyhandmer.wordpress.com/) - some very in-depth articles related to space

* [Modicum of Fun](https://jpieper.com/) - a blog post of Josh Pieper, who makes mjbots open-source motor controller

Other:

* [Julia's Drawings](https://drawings.jvns.ca/) - neat presentation of various technical concepts in programming. Unfortunately it's not active anymore.