AWS Lambda Extensions provide a new way to integrate Lambda with monitoring and security tools, enabling better observability into serverless applications. They allow vendors like Lumigo to deliver a better experience for developers, making it easier to develop robust and secure serverless applications. Lambda Extensions solve the problem of collecting telemetry data about AWS Lambda functions in a performant and cost-efficient way, providing a solution that is both performant and cost-efficient. The extensions run alongside code and receive updates via a poll-based API, allowing for real-time monitoring and analysis of function performance. They also enable vendors to customize the behavior of their extensions using Lambda environment variables and pass data between the main Lambda runtime and the extension through inter-process communication methods. The use cases for Lambda Extensions include observability without instrumentation, send telemetry data without latency overhead, security and governance, and more.