User Workflows and Request Routing

This chapter explains how to manage session data in serverless applications and how to reduce operational costs by moving user workflows and application assets out of Lambda functions.

In Chapter 9, you moved resource orchestration from Lambda functions into the AWS platform. This significantly reduced operational costs, but you can do even better. In fact, you can halve the costs for running your application by moving another coordination piece out of Lambda, this time related to user workflows. In the process, you can also make the application much more robust and user-friendly.

Up until this chapter, you used Lambda functions to generate HTML code for browsers. For example, once a user has uploaded a file, S3 will redirect them to the /confirm URL. This API resource is connected to the ConfirmUploadFunction, which will generate a download link for the results. The function will actually send a full HTML page, including the download link, back to ...