In this chapter, we learned that Lambda cannot scale infinitely due the execution limit set per AWS region. This limit can be raised by contacting the AWS support team. We also covered how the concurrency reservation at the function level might help you to protect your downstream resources, match the subnet size if you're using a VPC-enabled Lambda function, and control your costs during the development and testing of your functions.
In the next chapter, we will build a user-friendly UI on top of the serverless API with an S3 static-hosted website feature.
