DynamoDB Use Cases

Use Cases Overview

At its core, use cases is about doing one thing well inside your DynamoDB project. Once you understand the pattern, you can apply it consistently across features and teams.

Good use cases pays off across the whole codebase: fewer surprises, easier testing, and smoother onboarding. The snippet below is a solid starting point.

import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
import { DynamoDBDocumentClient, GetCommand, PutCommand } from '@aws-sdk/lib-dynamodb';

const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);

// reuse docClient across the module for efficient, typed access
await docClient.send(new PutCommand({ TableName: 'Orders', Item: { pk: '1' } }));

The DynamoDBDocumentClient maps plain JavaScript objects to DynamoDB item format for you.

Use Cases Example

import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
import { DynamoDBDocumentClient } from '@aws-sdk/lib-dynamodb';

const docClient = DynamoDBDocumentClient.from(new DynamoDBClient({}));
// docClient.send(new PutCommand(...)) etc.

• Start from a minimal Use Cases example and grow it only as needed.
• Keep configuration explicit so Use Cases behaves the same in every environment.
• Name things clearly so teammates understand your Use Cases at a glance.
• Add tests around Use Cases early to lock in expected behaviour.

Amazon DynamoDB Cheatsheet

Handy DynamoDB (AWS SDK v3) reference related to use cases.

How Use Cases Works in DynamoDB

Use Cases builds on DynamoDB's key-value and document model, where every item lives in a partition chosen by its partition key and is optionally ordered by a sort key.

The DynamoDBDocumentClient maps plain JavaScript objects to DynamoDB item format for you.

• Design access patterns first, then model keys around them.
• Prefer Query over Scan for predictable performance.
• Use expressions to read and write only what you need.
• Keep items small and avoid hot partitions.

Practical Guidance for Use Cases

In production, use cases should be cost-aware and resilient. Right-size capacity, handle throttling with retries, and lean on indexes to support your query patterns.

Common Mistakes

• Copying use cases snippets without understanding what each line does.
• Skipping error handling and edge cases when wiring up use cases.
• Leaving use cases untested, so regressions slip into production.
• Over-engineering use cases before you actually need the extra flexibility.

Key Takeaways

• Use Cases is a core part of working effectively with DynamoDB.
• Start small and keep use cases focused on a single responsibility.
• Apply consistent patterns so use cases scales across your project.
• Test and document use cases to keep it maintainable over time.