AWS Lambda Power Tuning is an efficient way to tune Lambda functions for cost and performance. It is a great tool that can help find optimal balance between cost and performance, based on specific optimization goals. This is a free, open-source tool that is available at GitHub.

The tool invokes a Lambda function multiple times under different memory configurations, and builds a visual representation of the impact on performance and cost.

Using Power Tuning tool early during the development cycle will set the correct expectation on memory and performance for Lambda functions. This is much more important for Java-based Lambda functions because Java-based functions tend to use more memory compared to other runtimes. Setting up a memory configuration of 128MB or 256MB will result is poor behavior from the beginning. Use this tool to find the correct memory configuration for your Lambda functions.