I love the "Avoid over design". I am working on the most over designed product ever. This applies to any programming and I am glad you put it first. There was an driver in the program I am currently working on that I just replaced because we moved to a new part (that will stay stable for about 30 years now). The old driver supported the device being removed and being replaced while the software was running. It was quite cool how all the hot swapping of the device was handled. It had every hardware resource available to it in use. DMA, interrupts, clock speed changes, multiple address. The driver implemented the kitchen sink.

It had built in options/change to the nth level. Problem was, it will never happen. It can never happen. This is an embedded system with a 15-30 year life span. In that time, it will change very little after development is complete. It will never have a wave soldered device removed while the power is applied. It will never get a second part (OK, there is a 0.1% chance). The DMA was not used for what DMA is good for, it was write and wait to complete in the higher level application code. Always will be.

The entire application is like this. Amazing functionality but it implements functionality never to be fully taken advantage of. As a result, we have 5X the number of files, it is 1/2 the speed it should be (and needs to be), 10X the number of functions.

I am glad you put over design at the top.