Chapter 10, Advanced Zappa Settings

1. AWS Lambda is designed to provide a serverless infrastructure. It instantiates the context on invocation request and then destroys itself after serving the request. AWS Lambda adds a little time delay for the initial startup and setting up the context. To avoid it, you can keep the Lambda instance in a warm state by setting up the schedule trigger using AWS CloudWatch. Zappa provides this feature by default and you can turn off this feature by setting the keep_warm attribute to false.
2. Cross-Origin Resource Sharing (CORS) is mechanism that allows a domain to access restricted resources from the different domain. 
3. Zappa provides an easy way of managing large size project as AWS Lambda has a limitation of uploading the build package with 50 MB but also have an option to service bigger size build packages from Amazon S3. In Zappa setting, you can slim_handler to true which will upload the build package on Amazon S3 and then configure the AWS Lambda against the uploaded build package on Amazon S3.