Amazon DynamoDB vs MongoDB

AWS's NoSQL workhorse: scales like a dream, but you'll pay for every query and pray you never need a JOIN meets the database for when you want to store json and pretend it's a schema. Here's our take.

Amazon DynamoDB

Nice Pick

AWS's NoSQL workhorse: scales like a dream, but you'll pay for every query and pray you never need a JOIN.

Pros

• Fully managed with automatic scaling and multi-AZ replication
• Single-digit millisecond latency for key-value operations
• Built-in security, backup, and in-memory caching with DynamoDB Accelerator (DAX)

Cons

• Pricing model can get expensive with high throughput or large datasets
• Limited query flexibility compared to relational databases (no JOINs, complex queries)

MongoDB

The database for when you want to store JSON and pretend it's a schema.

Pros

• Flexible schema allows rapid prototyping and iteration
• Native JSON-like document storage fits well with modern web apps
• Horizontal scaling with sharding is straightforward
• Aggregation pipeline is powerful for complex queries

Cons

• Lack of enforced schema can lead to messy data over time
• Joins are clunky compared to relational databases

The Verdict

Use Amazon DynamoDB if: You want fully managed with automatic scaling and multi-az replication and can live with pricing model can get expensive with high throughput or large datasets.

Use MongoDB if: You prioritize flexible schema allows rapid prototyping and iteration over what Amazon DynamoDB offers.

The Bottom Line

Amazon DynamoDB wins

AWS's NoSQL workhorse: scales like a dream, but you'll pay for every query and pray you never need a JOIN.