Azure App Services : Serverless functions

Azure offers a set of PAAS(Platform-As-A-Service) offerings known as App Services. Serverless functions are one of the services under the App Services Category.

A Serverless function is a piece of code that can be run independently. It can be triggered by certain events or invoked explicitly depending on the business requirements. Every time a serverless function runs it uses a certain amount of memory and Azure makes sure to run it on the appropriate server (depending on the language used to create the serverless function. You can create serverless functions in different languages like C#, Java, Javascript, Python and some others). So when you configure serverless functions in the Azure portal, you just specify the amount of memory you want to allocate. You do not have to be bothered about managing or scaling the server instances. Because of this, they are known as serverless functions. It is not because they don't run on servers. They do.

Here is an example of a serverless function :

There is a cool online shoe store where you go to buy your shoes. You go to their website and you want to get this brand new model xyz100, but that model is out of stock. So the store offers an option for you to be notified when the stock is replenished. You just need to provide your email which gets stored in their database. Behind the scenes, the store will create a serverless function that will be invoked whenever the model xyz100's stock is replenished. This function will then go to the database and get a list of people(including you) who have requested to be notified when this model is in stock and will send out emails to all of them.


In the case of serverless functions you are charged only when the function runs. You can always increase the amount of memory depending on your business needs. Since serverless functions are stand-alone and can be created in several different languages, they provide a lot of flexibility and freedom when it comes to the development process. You can have separate teams building and managing different functions. You can also choose the technology that best suits the requirement.