There have been two things that I have done several times over the last couple of years. The first one is having a bit of code control an inductive load of about an amp, be it a DC motor, stepper motor, or solenoid. My ToyBrain boards are a general solution to that problem, so I can just drop one in and write the code, instead of reinventing the wheel (or at least the controller for the wheel).
The other problem that I end up solving a lot is having a microcontroller drive an RGB led to make color fades and washes. This shows up in different forms in a bunch of my projects, and is not hard to do. However, I keep doing it, so I might as well have a PCB to make it easy. My goal is to have something that can drive up to about 30A, for three channels, with PWM. I usually use an ATTiny85 for this, along with current-regulated MOSFET drivers operating as current sinks. That actually leaves me with two pins left over for other purposes, so I’ll have some GPIO lines on the board as well.
The point of having general solutions like this is that it saves me from doing the boring parts of a job and lets me get directly to the interesting parts. These sort of programmable widgets are becoming so cheap and simple that they are effectively the dust that real things are made of. There is actually a term for this process: Ephemeralization. AM and FM radios are effectively ephemeral at this point. You can buy a single IC that does everything needed to receive AM/FM audio signals, or get the radios pre-made in units of a great gross from somewhere in China for pennies each. The case it is in no longer needs to look “like a radio” (whatever that means) because the parts are so small and flexible that you can put any sort of case around them and have a radio. Cameras (of a certain quality level, at least) have pretty much gone that way, cell phones and computers are going next.
What kind of world do you get when everything has a computer in it because it was cheaper and easier to build the thing around a general-purpose computing device instead of designing a single-use custom solution?