ASP.NET MVC vs Koa
When comparing ASP.NET MVC vs Koa, the Slant community recommends ASP.NET MVC for most people. In the question“What are the best backend web frameworks?” ASP.NET MVC is ranked 19th while Koa is ranked 33rd. The most important reason people chose ASP.NET MVC is:
The framework has many build-in tools, and many packages have been written targeting the framework.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Mature
The framework has many build-in tools, and many packages have been written targeting the framework.
Pro Cross platform
.Net Core can work on any platform.
Pro Widely used
It's pretty easy to find a job with it and there's plenty of documentation and tutorials around.
Pro Extensive documentation
There are a lot of resources available to get help.
Pro Fast
Asp.NET Core on Linux is fast accordingly to TechEmpower benchmarks.
Pro Asp.NET core provides balance between magic/agility and craftsmanship
You can get ordinary details quickly but with complete freedom to make your craft, knowing everything that is happening underneath the cloths. The highly modular system makes it possible to scale small applications to large ones with ease.
Pro It has more users than any other backend web framework
Getting your next contract is easy with this on your CV.
Pro Generator support from ground up
Using generators (a bleeding edge feature, even for Node.js) would clean up your code from the mess caused by all those callbacks; making your code more manageable.
Pro Extremely lightweight
Koa is very lightweight with just 550 lines of code.
Pro async/await keywords are supported and has transcended beyond generator functions
Generators functions are of course a huge plus, but at the time Koa team has transcended generations functions and shifted towards async/await style programming. It has made the Koa best framework available in the market.
Pro Development team has a proven track record
Koa is developed by the team behind a widely used node.js framework (express.js).

Pro Built for ES6
Cons
Con Core and full ASP.NET are bit confusing sometimes
While not in feature parity (yet) they are still apart and support sometimes funky combinations of features - full ASP.NET has all the bells and whistles but doesn't offer cross platform so you may have to do some research what you really need. That being said, it got a lot better in 2.0.
Con Expensive
You need to have the plate to maintain a site.
Con Community is relatively small
Con Not compatible with express style middleware
Koa uses generators which are not compatible with any other type of Node.js framework middleware.
Con Has no routes separated by HTTP method or URL pattern
Con Wrong Middle ware, security issue
