Flow-based programming is an interesting concept (which we tell a bit about in the article) and Node-RED is a powerful tool to turn this concept into reality (which we tell a lot about in the article).
Flespi easily fits in with its own MQTT broker while the specially developed flespi nodes allow automation of some flespi-specific processes.
Check some basic examples of using Node-RED together with flespi in the article and get your imagination prepared to come up with the more advanced cases.
https://flespi.com/blog/node-red-flespi-for-easy-automation-of-everyday-tasks
Tell us if you've been using FBP and how.