You can now develop your AWS Lambda functions using Node.js 4.3.2 in addition to Node.js 0.10.4. In addition to the leveraging new features in Node.js 4.3 such as ES6 support, Lambda functions written in Node.js 4.3 can now use standard Node.js callback conventions to specify error or return values for the function execution. Previously, returning values from a Lambda function required the use of methods specific to the Lambda programming model. See our documentation to learn more about implementing callbacks within Lambda functions.