When do I want to use one over the other?
Reading about both of them, they seem strangely similar, so I was wondering if someone with little experience would miss the pros and cons, and in which cases do the precedents succeed?
I think the best DynamoDB pros are well explained in the top answer What are the pros and cons of DynamoDB with respect to other NoSQL databases? :
The most notable feature of CouchDB not supported by DynamoDB is views (see here for a high-level description).