There’s the terrible thing I hope never to hear from people doing home automation, and which I’ve luckily managed to avoid in my only two homes in which I pursued automation.
To answer your question I have to show you common wire smart switches; however, the same could be accomplished (sans back lit LEDs) with battery powered wall mounted remotes (can even be mounted into a wall plate so it looks like a switch keypad I believe).
My proof of concept / test bed:
In-wall switch / keypad control via BOND