[ksatirli]

Personally and professionally, I have had a great experience with Datadog (https://www.datadoghq.com/) - plenty of integrations with various services, providers and a useable interface.

Prior to DD, I used ServerDensity (https://www.serverdensity.com/) - also a very mature tool and the technical blog written by their founder (https://blog.serverdensity.com/) has interesting tidbits from time to time.

I'm sure someone else will mention New Relic, too - great tool, but more expensive than the other two (though well worth it, if you need it)

[Prefinem]

Datadog looks awesome and was incredibly easy to setup and use. Thanks!

[ksatirli]

Glad you like them!