No real discussion of network protocols (or a network layer at all). For debugging in a distributed world, that's a valuable skill.
No real discussion of software deployment (although for backend services, docker might qualify). In a world of servers and PAAS's, it's helpful to know how to safely push the bits around.
Learn enough X to use it in your current project. Repeat for other projects.
1. OpenSSL and creating your own PKI as well as managing certs, renewals, and mutual client auth with x509 certs
2. basics of server security. IPTables and best practices around only opening ports you're using and other settings
Ok, .Net is not a language, it's a framework. C# ( & VB.Net) is the language.
There's a few Mono applications in Linux distros, but I think I can also count those on one hand.
So I'm not disagreeing it's possible, just very unlikely. (Even worse than PHP on Windows - sure, there used to be some high profile shops (5-10 years ago), but it always seemed like 10% or less. Also I'm not up to date on that regard.)
It's really best when your backend framework typically generates the Swagger definition from your API code, though. Spring, APIStar, and others will do this.
i was responding to that comment, in the context of a beginner the quick and easy to me seems like ruby. maybe im wrong, to each their own
you are also missing a big important part of being a full stack developer in 2018 and that is adwords and seo. Not being familiar with these topics will put you at a massive disadvantage in comparison to your peers and for your business.