AWS Lambda eliminates server management entirely, letting you run code in response to events without provisioning or managing infrastructure. Understanding common architecture patterns helps you build efficient serverless applications.
Event-Driven Architecture Patterns
The API Gateway plus Lambda pattern creates RESTful APIs where each endpoint triggers a Lambda function. This microservices approach scales automatically per endpoint and costs nothing when idle, making it ideal for variable-traffic applications.
Event processing pipelines use Lambda with S3, SNS, SQS, and DynamoDB Streams to create reactive workflows. An image uploaded to S3 can trigger a Lambda that resizes it, stores metadata in DynamoDB, and sends a notification through SNS, all without a single server.
Cold starts remain a consideration for latency-sensitive applications. Provisioned concurrency eliminates cold starts by keeping a specified number of function instances warm. For most workloads, however, cold start times of 100-500ms are acceptable and the trade-off in operational simplicity is worthwhile.