Here was some feedback from other users:

I have a k8s cron job that queries the FA eventLog API and sends them as DataDog events, then depending on severity a DataDog Event monitor will fire. Other than that, I feel rather blind.

we havent been able to upgrade quite yet, but 1.26 added a prometheus endpoint
right now we use the datadog jmx integration to get some stats, and we also do things like http monitoring

Here's the prometheus endpoint docs: https://fusionauth.io/docs/v1/tech/tutorials/prometheus/

FusionAuth does not have any plugins that directly write to 3rd party services like DataDog.

But with the API https://fusionauth.io/docs/v1/tech/apis/event-logs you can write an ingester.