> What if AWS or GCP goes down. It's a matter of trust and SLAs.

AWS does have a 100% uptime SLA on some of its services: Route53, for example [0]. Not saying that ApiTracker could not be a 100% uptime service (in fact, it looks like that's their explicit goal), just pointing out that AWS / GCP do have services that never "go down" barring global catastrophes.

[0] https://aws.amazon.com/blogs/architecture/a-case-study-in-gl... -- Route 53’s foremost goal is to always meet our promise of a 100% SLA for DNS queries – that all of our customers’ DNS names should resolve all the time.