The DevOps Engineer exam is finally GA! I took the Beta in December 2019 and received good news that I am now certified! Here are couple of tips you can use to get this certification.
In the exam guide you can find basic info on the content: https://cloud.google.com/certification/guides/cloud-devops-engineer/
I must admit that the exam guide is very accurate and mastering all the topics is the clue to nail this exam.
The main topics to concentrate on are:
SRE ca. 30% of the exam:
The books https://landing.google.com/sre/books/ might be a great resource but the coursera is good enough to cover topics like SLO, SLI, SLA, post mortem reports, error budget, blameless culture etc.
Stackdriver ca. 30% of the exam:
Make sure you know all the services of APM, Log Based metrics and integration with Fluentd. Understand advanced logs filtering.
Go through all the docs under: https://cloud.google.com/stackdriver/docs/
For beginners good summary of Stackdriver you can find in our book in the Monitoring Chapter:
DevOps ca. 20% of the exam:
Have basic understanding of tools like Terraform, Jenkins, Cloud Build, Spinnaker, Deployment Manager. I suggest finding some 101 on youtube e.g. https://www.youtube.com/results?search_query=spinnaker+demo
GKE ca. 10% of the exam:
I would say having the Cloud Architect Professional knowledge you should need 40-80h to prepare for this exam.
Good luck to all of you and let me know if you have any questions!