Background The boto3 SDK and the underlying botocore package are very large Python libraries. Just boto3 and botocore alone are over 50MB It can highly beneficial to reduce the size of these in a final build, especially in a serverless environment. AWS Lambda functions for instance only allow a maximum extracted size of 250MB, so this is over 1/5th of that alone. Additionally, a smaller package size also can dramatically improve the cold-start time of a function.

An introductory guide to using AWS DynamoDB