Why Azure Functions? Imagine that you have an application that needs to provide some specific functionality, but that still scales up when the call rate to your function increases. This is where Azure Functions provide a benefit. With Azure Functions, you only pay for the compute that your function needs at a specific instance in time, and it is immediately available.
To get started, head on over to https://azure.microsoft.com/en-us/services/functions and create a free account.
Because you only pay for the actual computing time you use when running Azure Functions, it is imperative that your code is as optimized as possible. If you refactor the Azure Function code and gain a 40% code execution improvement, you are directly saving 40% in your monthly expense. The more you refactor and improve your code, the more money you will save.