One of the biggest differences (problems, if you ask me) is that to build just about anything at all these days you have to know "a stack" which typically means

One of the biggest differences (problems, if you ask me) is that to build just about anything at all these days you have to know "a stack" which typically means at least two and usually three+ different languages: SQL, your app layer, and the client side. So you really can't master anything anymore, at least not like in the old days, because there's just so much more of it and you only have so many hours per week. But, this is probably inescapable. We have the internet now. You generally just can't write a monolithic app. It's going to be two apps (client and server) or one app that has to think about both client and server. And also Moore's Law went and died on us. So no more single-threaded... anything. Everything is threaded or parallel or etc etc now.