It was something like:
- Learn ASP, opps we meant ASP.NET web forms. Actually, we meant .NET MVC.
- Oh no, the world wants APIs ... please learn WCF. Actually, we meant .NET Web API.
It seems things have finally calmed down with .NET core. But, along with the MS frameworks you also need to have good command over C# and data access / manipulation utilities such as LINQ, Entity Framework, etc. If you happen to be working with MSSQL Server as I was -- you had to learn it and all of its quirks.
I will say the tooling, once learned, was pretty good everywhere (except WCF in terms of configuration). I can't say that for a lot of front-end utilities, which I think results in a lot of configuration pain and StackOverflow searches.
I do find the answers / guidance on configuring front-end much higher quality than most things in the MS ecosystem, though.
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My intent here isn't to bash MS so much as it is to point out that the breadth of things you actually have to learn for front-end development is less than some other ecosystems. We're a part of a privileged profession where income and demand is high, so I do expect re-skilling to be an ongoing process.