Regarding memory, I recently changed to try to not use dynamic memory, or if I need to, to do it once at startup. Often static memory on startup is sufficient.

Instead use the stack much more and have a limit on how much data the program can handle fixed on startup. It adds the need to think what happens if your system runs out of memory.

Like OP said, it's not a solution for all types of programs. But it makes for very stable software with known and easily tested error states. Also adds a bit of fun in figuring out how to do it.

This is the way. Allocate all memory upfront. Create an allocator if you need to divy it up dynamically. Acquire all resources up front. Try to fit everything in stack. Much easier that way.

Only allocate on the heap if you absolutely have to.

In recent years I had to write some firmware code with C and that was exactly the approach I took. So far I never had need for any dynamic memory and I was surprised how far I can get without it.

I've been looking into Ada recently and it has cool safety mechanisms to encourage this same kind of thing. It even allows you to dynamically allocate on the stack for many cases.