An introduction to Amazon Simple Workflow Service for coordinating distributed application components. Explains decider and worker roles, task-based workflow execution, reliability features like retries and timeouts, and provides Ruby code examples for registering workflow types and processing tasks.

A review of Amazon DynamoDB key-value database service. Compares to SimpleDB, explains Dynamo's white paper origins and influences on Cassandra and Riak, highlights predictability of performance with configurable throughput, discusses trade-offs like 64KB item limit and lack of easy table cloning, and praises ease of setup over self-administered NoSQL databases.

Code examples demonstrating Amazon SQS queue operations in both Node.js and Ruby. Shows how to create queues, send messages, and receive messages using AWS SDKs in both languages, comparing API patterns and highlighting event-driven use cases for decoupling application components.

Ruby example using Amazon Web Services SDK to publish messages to Simple Notification Service topics. Demonstrates getting SNS interface, finding topic by ARN, and publishing messages which can be delivered as SMS or emails, perfect for form-based notifications in Ruby applications.