I am the sole author of an actual OS and remain responsible for over 40,000 placements worldwide. Having this in an actual product (running on a 100MHz MCU) keeps the pressure on. You can see it in this post contending with the open Internet. I am willing to share development details. I started it from scratch in 2011.

https://www.reddit.com/r/jnior/s/D6Az4O93SG