In this Talk, key characteristics of AWS Lambda functions are covered, including service architecture, composition, and optimization of Node.js code. The two operational models of Lambda, asynchronous and synchronous invocation, are explained, highlighting the scalability and availability of the service. The features of Lambda functions, such as retries and event source mapping, are discussed, along with the micro VM lifecycle and the three stages of a Lambda function. Code optimization techniques, including reducing bundle size and using caching options, are explained, and tools like webpack and Lambda Power Tuning are recommended for optimization. Overall, Lambda is a powerful service for handling scalability and traffic spikes while enabling developers to focus on business logic.