Both frontend and backend work. The same result one could expect if I had spend the time to learn it and then debug for this one specific issue for ages. What does not work is the “set” button as well as the mDNS. The first I am sure a good program could fix, the other is due to a lack of updates to the old phone to get mDNS working.

We are only taking about an ESP32 project here, not an actual website. Just for convenience for data input and output this is far(!) better than a display and some buttons… Which is what I used to do in the past decade.