Is there a security system that allows input signals from different providers / systems and aggregates them? For example, it can use presence / motion sensors coming from ecobee and echo flex, ring doorbell and blink outdoor cameras, nest CO/Smoke detectors, etc. (and not necessarily these brands, those were the first that came to mind)? I have quite a few IoT devices, and I'd like them to work in ensemble. I'd also want to choose the best for each task, but have them work together (through a hub that I pay a monitoring service for) to paint a coherent picture of the house state.
I'm a software engineer and a hacker at heart, so I don't mind creating complicated IFTTT or similar scripts -- or even programming and paying for a lambda function -- to achieve that goal.