Introduction
In the previous chapter, you learned about Azure Durable Functions and the distributed, stateful, and serverless workflow they enable. You created several workflows, including one that managed the addition of users. This workflow is useful, but not ideal. The incredibly common, totally zero value-add task of producing user sign-up software is now available as a highly secure service from most cloud providers, notably Azure Active Directory B2C, which you will learn how to use later in this chapter.
Security is a serious consideration in all applications. With security, we are effectively trying to keep the system that we have built under our control and allow each user to interact with it safely. Some of the systems we have built so far in this book are not ideal from this point of view. At the moment, any random internet user can create users, submit orders as that user, and add extra products to our store. They can attempt a Denial-of-Service (DoS) attack, flooding your service...