Software for a Raspberry Pi mirrorless camera project

I have a HQ camera on order with the intention of building a mirrorless camera similar to a recent reddit post here. I have a good idea on what to do for the hardware, but I’m stuck on software.

My thought is to have a 4" capacitive touch screen on the back for controls and a button on top for ‘shutter’. RPi-Cam-Web-Interface seems to do what I want, but I was wondering what else was out there. I don’t mind building one myself, but having something to fork or start from would be very helpful. If that were the case I’d probably use Nodejs exec() commands, but I’m not sure how things like live preview would work. I fount this blog post on how to stream the live preview using VLC which may work.

Any other ideas?