/daɪˈnæmoʊ diː biː/
n. — "AWS serverless key-value firehose mocking MongoDB's document bloat."
DynamoDB is Amazon's fully-managed NoSQL key-value and document store delivering single-digit millisecond latency at unlimited scale via automatic partitioning, designed for high-throughput workloads like shopping carts/IoT/gaming leaderboards. Unlike self-hosted MongoDB, DynamoDB eliminates servers/ops with partition keys (hash) + optional sort keys enabling range queries, Global Tables for multi-region replication, and DAX caching—billed per read/write capacity unit.
Key characteristics and concepts include:
- Partition key hashing distributes items across unlimited storage, auto-scaling throughput without manual sharding wizardry.
- Strongly consistent reads vs eventual consistency, ACID transactions across multiple items since 2018.
- TTL automatic deletion, Streams for Lambda triggers, Global Secondary Indexes for ad-hoc queries.
- Serverless pricing (~$0.25/million writes) vs MongoDB Atlas clusters, but 400KB item limit mocks large documents.
In e-commerce workflow, PutItem user_cart (PK=user_id) → UpdateItem add_item → Query by PK+sort(timestamp) → Streams trigger inventory Lambda → Global Table syncs cross-region.
An intuition anchor is to picture DynamoDB as infinite vending machines: drop partition key, get item instantly anywhere—AWS restocks/replicates behind glass while MongoDB needs warehouse management.