1.5. Key Developer Tools & Access Overview

💡 First Principle: Every interaction with AWS — whether from your terminal, your code, or the console — goes through the same API. The tools just provide different interfaces to it.

What happens if you understand the CLI but not the SDKs? You can manage resources manually but your applications can't interact with AWS programmatically. What if you understand SDKs but not IAM? Your code works locally but fails in production because it lacks permissions. For example, a developer who runs aws s3 ls locally sees their buckets, but the same code in Lambda returns AccessDenied because the execution role lacks s3:ListBucket. These three tools — CLI, SDKs, and IAM — form the developer's daily toolkit.

Think of them as layers: IAM is the security guard (who's allowed in?), the CLI is your command-line remote control, and the SDK is the library your application code uses to talk to AWS services directly.