Serverless backend patterns enable event-driven, scalable application architectures where cloud providers manage infrastructure, allowing developers to focus on business logic while paying only for actual compute time. These patterns—built primarily on AWS Lambda, Azure Functions, and Google Cloud Functions—provide automatic scaling, high availability, and reduced operational overhead for modern cloud-native applications. The key to successful serverless backends lies in understanding function invocation models, optimizing cold start performance, designing stateless workflows, managing dependencies and secrets, and implementing robust error handling with idempotent operations. While provisioned concurrency and proper architecture patterns solve most performance concerns, the real power emerges when combining messaging services (SNS, SQS, EventBridge), API gateways, and orchestration tools (Step Functions) to build resilient distributed systems.
What This Cheat Sheet Covers
This topic spans 25 focused tables and 209 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: Function Invocation Patterns
| Pattern | Example | Description |
|---|---|---|
API Gateway → LambdaClient waits for response | • Caller waits for function completion • used for HTTP APIs, returns response directly • errors propagate to caller immediately | |
S3 event → Lambda (queued)Automatic retry 2x | • Function is queued for execution • caller receives immediate acknowledgment • supports automatic retries (up to 2 attempts) and destinations for success/failure | |
Lambda polls SQS queueBatch size: 10 messages | • Lambda polls stream/queue (SQS, Kinesis, DynamoDB Streams) and invokes function with batches • enables partial batch failure handling | |
AWS SDK: lambda.invoke()Synchronous or async | • Programmatic function trigger via SDK/CLI • caller specifies InvocationType (RequestResponse, Event, DryRun) • useful for testing and orchestration | |
https://xyz.lambda-url.us-east-1.on.aws/Public HTTPS endpoint | • Dedicated HTTP(S) endpoint for Lambda without API Gateway • supports response streaming, CORS, IAM or no authentication • ideal for simple APIs |