I created a 4 channel remote switch server with Node and Socket.io on Raspberry pi 4. You can use it for control home devices remotely. You can add/edit switches in .json files on /switches.
I hope you join my project and learn new things😀
$ git clone https://github.com/XristosApatsidis/control-gpio-remotely.git
$ cd control-gpio-remotely
$ npm install
$ npm run-script nodemon
For example I use 5V, GND 2, 3, 14, 17 pins on Raspberry pi 4.