Mongo works really well for backends to test your UI against in coding bootcamps. Dead simple CRUD storage and access model. As a mock React data store, it'd be hard to find simpler.
DynamoDB is a managed service that scales far beyond Mongo and truthfully far beyond what any of us here would be seriously discussing.
With regard to complex schemas and related data, both DynamoDB and Mongo are harder to deal with once you've past a trivial size. If all you need is basic CRUD with limited or no joins, Mongo could suffice to a large deployment, but if you're mostly accessing by primary key, DynamoDB will soundly eat its lunch performance-wise and for cheaper.
If you need to join related data (or just find them convenient), relational models work famously well, and usually up the point where you have 10 million simultaneous users.
Mongo more and more is being relegated to niches where the problem just happens to exactly fit Mongo's feature list, which unfortunately for Mongo encompasses ever-narrowing gaps in the other options' offerings.
Mongo can't match the scale or economy of DynamoDB and can't match the flexibility of relational. That's why fewer and fewer treat it as their go-to database nowadays.
DynamoDB is a managed service that scales far beyond Mongo and truthfully far beyond what any of us here would be seriously discussing.
With regard to complex schemas and related data, both DynamoDB and Mongo are harder to deal with once you've past a trivial size. If all you need is basic CRUD with limited or no joins, Mongo could suffice to a large deployment, but if you're mostly accessing by primary key, DynamoDB will soundly eat its lunch performance-wise and for cheaper.
If you need to join related data (or just find them convenient), relational models work famously well, and usually up the point where you have 10 million simultaneous users.
Mongo more and more is being relegated to niches where the problem just happens to exactly fit Mongo's feature list, which unfortunately for Mongo encompasses ever-narrowing gaps in the other options' offerings.
Mongo can't match the scale or economy of DynamoDB and can't match the flexibility of relational. That's why fewer and fewer treat it as their go-to database nowadays.