DynamoDB VPC Endpoints

VPC Endpoints sits at the heart of security in DynamoDB. This guide walks through the concept step by step, with examples, a cheatsheet, and common mistakes to avoid.

VPC Endpoints Overview

VPC Endpoints is a building block you will reach for often in DynamoDB. It keeps related logic together and makes your intent obvious to reviewers and future maintainers.

When you learn vpc endpoints properly, you avoid the guesswork that leads to bugs and rework. The example below shows the shape you will use in most real DynamoDB projects.

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.

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

Amazon DynamoDB Cheatsheet

Handy DynamoDB (AWS SDK v3) reference related to vpc endpoints.

Operation	Command	Purpose
Create/replace	`PutCommand`	Write an item
Read one	`GetCommand`	Fetch by primary key
Update	`UpdateCommand`	Modify attributes
Delete	`DeleteCommand`	Remove an item
Query	`QueryCommand`	Efficient key-based read
Scan	`ScanCommand`	Full-table read (avoid)
Transaction	`TransactWriteCommand`	Atomic multi-item writes

How VPC Endpoints Works in DynamoDB

VPC Endpoints 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 VPC Endpoints

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

Concern	Recommendation
Performance	Query by key; avoid table scans
Cost	Use on-demand or right-sized provisioned capacity
Modeling	Design for known access patterns
Reliability	Retry throttled requests with backoff

Common Mistakes

Skipping error handling and edge cases when wiring up vpc endpoints.
Leaving vpc endpoints untested, so regressions slip into production.
Over-engineering vpc endpoints before you actually need the extra flexibility.
Ignoring documentation, which makes vpc endpoints hard for the next developer to change.

Key Takeaways

VPC Endpoints is a core part of working effectively with DynamoDB.
Start small and keep vpc endpoints focused on a single responsibility.
Apply consistent patterns so vpc endpoints scales across your project.
Test and document vpc endpoints to keep it maintainable over time.

Pro Tip

Pair vpc endpoints with automated tests from day one. It is far cheaper to catch DynamoDB regressions in CI than in production.