I recently undertook the the Contentful certification exam (managed to pass on my second attempt 😂).
The exam is multiple choice and really does test your knowledge of Contentful.
If you're interested in taking the exam read through the "Contentful certification study guide" watch all the videos and the slides...
I found after my first attempt that I needed to brush up on my knowledge of the different API's and SDK's.
The exam costs $250.