Status

1. An EventBridge schedule fires every ten minutes.
2. It invokes a Python Lambda that requests each service concurrently, timing the response to its headers and following redirects to the final status code. A second connection reads the TLS certificate and its expiry date.
3. A service is down on an error or a non-2xx/3xx status, degraded above one second, and operational otherwise.
4. The Lambda writes the results to status.json in this site's S3 bucket, with a 60-second cache lifetime, and CloudFront serves it.
5. This page fetches that file on load and again every minute.
6. All of it, schedule to permissions, is Terraform in this site's repository.

Checks run from AWS us-east-1, so latency is measured from Virginia, not from you.