TypeScript satisfies + AWS SDK v3: The Pattern That Changed How I Write Commands

Last week, we migrated 12 of our Lambda handlers to TypeScript 5.5 and discovered the satisfies operator, which has changed how we write commands with AWS SDK v3. But what surprised us was how it affected our testing and validation pipelines.

Introduction to TypeScript satisfies

The satisfies operator is a new feature in TypeScript 5.5 that allows you to narrow the type of a value without changing its runtime behavior. This can be useful when working with complex types, such as those found in the AWS SDK v3.

type DynamoDBCommand = {

TableName: string;