AWS CDK Constructs Explained: L1, L2, and L3 with Python

If you've ever looked at two CDK stacks doing the same thing and wondered why one is 200 lines and the other is 20, the answer is almost always which level of construct the author chose. This post breaks down all three levels — L1, L2, and L3 — using a consistent real-world example so you can see exactly what each abstraction buys you. Background: What Is AWS CDK? The AWS Cloud Development Kit (CDK) is an open-source framework that lets you define cloud infrastructure using familiar programming languages — Python, TypeScript, Java, and more. Under the hood, CDK synthesizes your code into AWS CloudFormation templates, which are then used to provision resources. The key advantage over raw CloudFormation YAML is that you get the full power of a programming language: loops, conditionals, type checking, reusable classes, and IDE support. Instead of copying and pasting 300 lines of YAML every time you need a Lambda function, you write a Python class once and reuse it everywhere. CDK apps are