A developer deployed a new version of an AWS Lambda function. To validate it, the developer must route 50% of traffic to the new version and 60% of traffic to the current version. What is the MOST operationally efficient way to accomplish this?

Lambda aliases provide a built-in traffic shifting mechanism, allowing you to easily distribute traffic between two Lambda function versions based on specified weights. This is the most operationally efficient method as it's designed specifically for this use case and integrates directly with Lambda's versioning. Incorrect options: Route 53 cannot directly route traffic to different Lambda versions; it routes to endpoints like API Gateway or load balancers. While API Gateway can manage traffic, the question specifies routing 50% to the new version and 60% to the current version, which sums to 110% and is an impossible split. Even if the percentages were valid, Lambda aliases are a more direct and efficient solution for Lambda-specific traffic shifting. Event source mappings are for configuring how event sources (like SQS, Kinesis) invoke a Lambda function. They do not have built-in capabilities to split traffic between different function versions based on weights.