I did quite a bit of experimentation with home automation systems (HomeSeer, Home Assistant, Domoticz and so on) and decided that the best (at least for me) and the most control giving solution is NodeRED - https://github.com/node-red/node-red.
You can create pretty complex flows with many already available nodes but if you want something custom - it's trivial either to add JS functions or to create your own node from scratch. Currently running it in a Docker container on an Intel NUC :)
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 :)
I've been using Node Red for a few automation things too, basically as a self-hosted ifttt/zapier, and it's been working well. I would recommend it beyond home automation for the kinds of things that are "too small" to warrant their own code project and deployment setup but are still important enough to be automatic. This includes things like checking a webpage every 10 minutes and sending a text if it changes, or remapping webhooks between random services.
Exactly! My NodeRED besides doing some home automation actually does a lot more "ops" work for me:
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 :)
Another option: Use HomeAssistant for the user friendly interface (fancy buttons, value display, you-name-it), and use NodeRED for the logic. The HomeAssistant nodes are quite decent, it‘s how I‘ve set things up at home.
Which home automation platform you eventually ended up with on NUC? I recently bought NUC to do the same and I cannot decide between Home Assistant, openHAB so I am running them both and playing a bit with Hue lights/Belkin switch. I have not tried Domoticz - I know it's very lightweight but not too feature heavy. Eventually I want to replace Alexa, using Snips.
I have both NodeRED and Home Assistant but lately Home Assistant doesn't do pretty much anything anymore and everything goes through NodeRED :)
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 :)