Why are you using Dynamodb wrong???
Dynamodb is a oversized key-value store database. People are concerned with the limitations of it (table nesting, document size, etc), but they obviously haven’t figured out serialization.
Store your blobs, or objects, and keep intelligent keys. If the blobs are too big, then gzip them before storing and save as Binary. You have to do this because they don’t allow you to have multiple indexes like Mongo.
Stay laughing.