AWS Lambda was announced at Re:Invent 2014 as a service that runs code in response to events and automatically manages the compute resources necessary to handle potentially millions of simultaneous requests. When it was first released, Lambda was limited to either responding to specific events (objects being stored on S3, SNS notifications, etc.) or direct invocations through the AWS API. Since then, AWS has also launched AWS API Gateway which aims to allow Lambda to serve as the backend to APIs and standard web applications. AWS is slowly removing the need to run managed servers, allowing developers to focus on writing code instead of managing memory, disk space, etc.