Let's briefly look at what we learned about AWS Lambda functions. Amazon Web Services was the first web service platform to launch the serverless computing module Lambda, written in Lambda functions. Lambda functions are stateless and have no affinity with the underlying infrastructure. Lambda functions are executed in response to the events. These events could be an HTTP request, a change of the data in the S3 bucket, a change in a DynamoDB table, or a change in Kinesis or SNS. Lambda functions replicate faster in response to events, and descale as the number of events goes down.
In this chapter, we will be covering various methods of deploying Lambda functions, looking at how we can painlessly deploy to multiple environments, unit test, system test, and integration test the Lambda function. We will also...