There are multiple articles out there about Google Cloud Professional Architect Certification, so I'll just describe my personal experience and impressions from this exam and my preparations to passing this certification.
On the outside, this exam is a typical multiple-choice test, with some questions having more than one answer. There is no lab environment where you need to perform some actions, like some other providers like Cloudera and Microsoft started to incorporate into their tests. The test has 50 questions and you get 2 hours to complete them.
The biggest difficulty is that many questions revolve around three case studies which represent fictitious scenarios for companies migration to the GCP. The intent, I think, is to evaluate how you professionally perform in the Cloud Architect role, rather than around the Google Cloud platform itself. That makes you balance between functional and non-functional requirements and consider cost, existing infrastructure and processes, regional vs global representation, scalability and latency, among others. The answers could be different depending on what is emphasized in the particular question.
I guess the most peculiar thing about the exam is that it does not provide any feedback, so it is difficult to judge which areas need improvement.
Previously, you could only take this exam in one of the test centers but now it is available online too, "thanks" to the COVID-19 situation in the world. Many test centers started to open now though, so you can choose what is most suitable to you. I have to warn though that if you are taking it from home there are some requirements to your home environment, webcam, and computer that you need to check, and the dedicated proctor is going to watch over you during the exam. Logistically, it is simpler to get it from the test center.
Coursera's Preparing for the Google Cloud Professional Cloud Architect Exam gives a good overview of the certification and provides some good points for your preparation. It is also free. This course is a part of a larger "Cloud Architecture with Google Cloud Professional Certificate" program, however I found it too bloated and there are better paid options from other learning providers.
The one that I liked is Google Cloud Certified Professional Cloud Architect by Matthew Ulasien. It is just over 30 hours long and includes access to 15 labs that will help to cement your knowledge of the GCP. There is also a sample test you could try multiple times with different questions, and a Lucidchart multi-page diagram to help you navigate the lessons and GCP resources. Overall, this course provides an excellent value for the money.
Speaking of labs, Qwiklabs has a vast catalog of hands-on labs on almost all aspects of GCP and this resource is invaluable if you want to dive into more practical usage of the Google Cloud platform.
Finally, I found that the Professional Cloud Architect – Google Cloud Certification Guide book is very well structured and, despite several insignificant errors, provides complete information necessary to pass the exam and will help to fill the gaps in online lessons.
Pay special attention to VMs, images and managed instance groups, storage options, Kubernetes gcloud and kubectl commands, networking options and connection to on-premises data and, of course, case studies.
A word of encouragement to all candidates: do not be afraid, the exam is not as difficult as it seems, and with about 2 months of studying, following the guide above, it is possible to prepare for the test. Of course, practical experience would help immensely, and I recommend to get a GCP free-tier to explore it in detail, as well as going through the related Qwick Labs.
Lastly, don’t forget to take the practice exam!
This is my certificate and I wish all the best to everyone preparing for this exam. Don't worry, here is a cat for you: