Testing
AWS CDK has two testing approaches that serve different purposes and are commonly confused: 1. Fine-grained assertions (hasResourceProperties, hasResource, resourceCountIs) — assert specific properties of specific resources 2. Snapshot tests (toMatchSnapshot) — assert the entire synthesized CloudFormation template hasn't changed Most CDK projects use one or the other exclusively,
Testing
AWS SQS and SNS are foundational to event-driven architectures on AWS. Testing code that uses them requires a layered approach: fast unit tests with mocked clients, integration tests against LocalStack or a real AWS sandbox account, and end-to-end tests for Lambda triggers. Layer 1: Unit Testing with
Testing
AWS SQS and SNS are everywhere in serverless and microservice architectures. They're also surprisingly easy to test badly. This guide covers the three layers of SQS/SNS testing: unit tests with SDK mocks, integration tests with LocalStack, and end-to-end tests for complete async flows. The Three
AWS
AWS SAM (Serverless Application Model) gives you infrastructure-as-code for serverless applications, but testing SAM applications before deployment has historically been painful. The sam local toolchain has matured significantly — this guide covers how to use it effectively for unit tests, local integration tests, and pre-deploy validation. Why SAM
Testing
AWS SAM CLI lets you invoke Lambda handlers locally with sam local invoke and spin up a local API Gateway with sam local start-api. Use it for fast feedback on handler logic and event parsing before deploying to AWS. Combine with environment variable overrides and Docker for CI integration.
Testing
AWS Glue ETL jobs are PySpark scripts that run in AWS-managed Spark clusters. Testing them properly is challenging: you need Glue-specific libraries (GlueContext, DynamicFrame), access to AWS services, and a Spark runtime. This guide covers the full testing stack: local development with the Glue Docker container, unit testing
AWS
AWS EKS adds a Kubernetes control plane on top of AWS infrastructure, which means you're testing both Kubernetes abstractions and AWS-specific behavior. A Pod that works in local kind or minikube may fail in EKS due to IAM Roles for Service Accounts (IRSA), VPC CNI networking, or
AWS
Testing containerized workloads on AWS ECS and Fargate requires a different mindset than testing traditional server-based applications. Your containers are ephemeral, networking is abstracted, and the control plane sits between you and your code. This guide covers practical integration testing patterns for ECS and Fargate workloads. Why ECS/Fargate
Mobile Testing
AWS Device Farm lets you run tests on real Android and iOS devices hosted in AWS data centers. Instead of managing a physical device lab, you upload your app and test scripts, pick devices, and run tests in parallel. This guide covers how Device Farm works, how to set it
AWS
CloudFormation templates grow from 50 lines to 5000 lines. They define VPCs, IAM policies, RDS instances, and load balancers. A misconfigured security group or a missing IAM permission isn't a code bug — it's an infrastructure outage or a security incident. Testing CloudFormation templates rigorously is not
LLM Testing
AWS Bedrock Model Evaluation lets you run structured quality assessments against Bedrock-hosted models — comparing outputs against ground truth, scoring on custom criteria, and tracking results across model versions. Here's how to set up automated evaluation pipelines using the Bedrock API and boto3. What Bedrock Model Evaluation Offers
API Testing
AWS Cognito provides user authentication, authorization, and identity management for AWS-hosted applications. Testing Cognito integrations is critical — a misconfigured user pool can lock users out, a broken Lambda trigger can block all signups, and a wrong JWT audience claim can silently reject valid users. This guide covers testing Cognito