Azure Functions is a serverless computing platform offered by Microsoft as a part of Azure Cloud. All design goals are the same as other serverless/FaaS services, and Azure Functions enables us to execute our application logic without managing our own infrastructure.

Azure Functions runs a program in the form of scripts when it is triggered by events. The current version of Azure Functions supports language runtimes such as C#, F#, PHP, Node.js or Java. It is natural for Azure to support C# and F# as first-class languages for their functions because they are Microsoft-owned programming languages. In any case, the only GA-supported languages are C#, F#, and JavaScript (Node.js) anyway.

With C#, F#, or .NET languages, Azure Functions allows us to install dependencies via NuGet, the infamous package manager for .NET. In case we are writing JavaScript with Node.js, Azure also provides access to NPM for package management.

Similar to other cloud providers, Azure Functions has an advantage when accessing other Azure services, for example, Azure Cosmos DB, Azure Event Hubs, Azure Storage and Azure Service Bus.

It is really interesting to note that the pricing model of Azure Functions is somewhat different from the offering of Amazon or Google. In Azure, there are two kind of pricing plans that may fit different needs.

The first one is the consumption plan. It is a similar plan offered by other cloud providers, where you pay only for the time that our codes are executed. The second one is the app service plan. Functions in this context are considered part of the app service for other applications. If functions fall into this category, we do not need to incur additional cost.

An interesting feature of Azure Functions is its triggering and binding mechanism. Azure Functions allows a definition of how to trigger a function and how to perform data binding of the input and the output for each function, in a separated configuration. These mechanisms help to avoid hardcoding when we call functions and when we transform data in and out through the calling chain of functions.