TCP/IP network programming in C on Linux is good fun. All the advanced features of the stack are at your disposal, and you can do lot of interesting things in user space without getting into kernel ...

This engineering specialization provides students with the fundamentals of embedded operating systems including a working understanding of how to configure and deploy a Linux based Embedded System.

Microsoft and Linux are adding AI and Rust to their pipelines. Microsoft is leaning much harder into AI development than Linux. Both are expanding Rust, but neither OS will be fully Rust soon.