1. Complex healthchecks for my side project webhookrelay.com (tests backend functionality every 30 seconds) 2. Normal HTTP healthchecks for all my websites - webhookrelay.com, keel.sh and few other backing services such as drone itself. 3. Updates homebrew formula hash when a new release is out (there's a super easy to use github integration that allows you to modify files) 4. Receives and processes emails from Mailgun about delivery failures.
So yeah, probably the best self-hosted IFTTT/Zapier out there :)
That said I only use smart devices I control over my LAN and none that require I interact with a companies provided API.
I also run more things on my NUC like drone.io build server to run my tests and few more things. I ended up just having a docker-compose file for all my things as opposed to installing services I use through things like HomeAssistant.
The only downside is that it's not user friendly for non-tech people as you would still have to know few things such as what is HTTP server and how do devices talk to each other. It's not as easy as plugging in Google Home and just talking to it. But on the other hand, I only use my google home to: 1. Set timer when I am cooking 2. Send webhooks to my NodeRED to control things.
I don't have Nest currently, although I did use it several years ago, can't say it's very smart :)