Using the the Amazon CloudWatch Evidently extension

You can use Amazon CloudWatch Evidently to safely validate new features by serving them to a specified percentage of your users while you roll out the feature. You can monitor the performance of the new feature to help you decide when to ramp up traffic to your users. This helps you reduce risk and identify unintended consequences before you fully launch the feature. You can also conduct A/B experiments to make feature design decisions based on evidence and data.

The AWS AppConfig extension for CloudWatch Evidently allows your application to assign variations to user sessions locally instead of by calling the EvaluateFeature operation. A local session mitigates the latency and availability risks that come with an API call. For information about how to configure and use the extension, see Perform launches and A/B experiments with CloudWatch Evidently in the Amazon CloudWatch User Guide.