AWS Lambda has announced a new integration with Amazon Elastic File System (Amazon EFS), allowing developers to add persistent storage to their serverless functions, enabling stateful applications and improving performance for tasks like machine learning and virus scanning. AWS Lambda is designed as a stateless service, but the addition of EFS enables it to be used in conjunction with other tools like step functions or EC2 instances for more complex state machines. The new integration also includes security controls, such as IAM authorization and access points, to protect data access. Additionally, Amazon Cloudwatch will provide key metrics about the performance of the EFS-Lambda connection, and New Relic's Infrastructure monitoring tool will gather these metrics for further analysis.