With the explosive growth of online services, we’ve seen over 2020, it’s clear the Public Cloud is going to pervade our lives increasingly. The Internet is full of articles listing differences between platforms. But when we look closer, it all seems to fall into same groups: compute, storage, and networking. Yes, naming is different, but fundamentals are pretty much identical between all major providers.

Last time

We explored a few differences between AWS S3 and Azure Storage. On paper both Azure and AWS offers are comparable: Azure has Functions and AWS calls theirs Lambda. But subtle differences begin to show up right from the beginning…

Creating resources Azure vs AWS

Without even getting into writing any code yet we are greeted by the first difference: AWS allows to either create standalone functions or to provision Lambda Apps that are basically CloudFormation templates for a function and all related resources such as CodeCommit repo, S3 Bucket and project pipeline for CICD. Azure on the other hand always prompts to structure functions by sitting them inside a Function App. The reason for doing that is, however, slightly different: Function App is a collection of functions that share the same App Service Plan.

Serverless Invocation

AWS does not assume any triggers and we’d need to add one ourselves. Adding an API Gateway as a trigger is totally possible and allows for HTTPS setup if need be. But because trigger is external to the function – we need to pay closer attention to data contract: API reference is helpful but the default API gateway response of 500 makes it hard to troubleshoot.

Portal editor functionality

Another obvious difference between the platforms is built-in code editor experience. In AWS it is only an option for interpreted language runtimes (such as Node.js, Python and Ruby):

finding code editor in AWS portal is very easy
if runtime is not supported, you would get a blue message

Azure has its own set of supported runtimes. And of course, things like .NET and PowerShell get full support. There’s however one gotcha to keep in mind: Linux hosting plans get limited feature set:

rich experience editing code in Azure
even though .net is a first party runtime - using Linux to host it ruins the experience

.NET version support

AWS supports .NET Core 2.1 and 3.1 and conveniently provides selection controls, while Azure by default only allows for version 3.1 for newly created function apps:

AWS is an open book: picking runtime version is easy
Azure makes it a no-choice and might look very limiting, but read on...

At first look such omission is very surprising as one would expect more support from Microsoft. This however is explained in the documentation: .NET version is tied to Functions Runtime version and there is a way to downgrade all the way down to v1.x (which runs on .NET 4.7!):

it is possible to downgrade Function Runtime version. but there are limitations and gotchas


Language support.NET Core 2.1, .NET Core 3.1, Go, Java, Node.Js, Python, Ruby, PowerShell Core.NET Core 3.1, .NET Core 2.2, .NET 4.7, Node.Js, Python, Java, PowerShell Core
OSLinuxWindows or Linux (depending on runtime and plan type)
TriggersAPI Gateway, ELB, heaps moreBuilt-in HTTP/Timer, heaps more
HierarchyFunction or Function appFunction App
Portal code editor support Node.JS, Ruby, PythonNode.js, .NET, PowerShell Core,