I highlighted the quote that bothered me; it may not be relevant to your point but I actually think it is. Why is Node.js popular now? Because people want to c

I highlighted the quote that bothered me; it may not be relevant to your point but I actually think it is. Why is Node.js popular now? Because people want to create web applications that are responsive without requiring the client to constantly poll the server to see if there's new data, and Node.js does that better than existing tools. Why are NoSQL databases popular now? Because right now, it's a lot cheaper to scale up by buying more computers than it is to scale up by buying better computers, and current relational databases are bad at scaling up that way (compared to other parts of the stack). Now, I think that NoSQL sometimes throws out the baby with the bathwater, and I do think there are cargo cult NoSQL users who are convinced that if they go around throwing out babies they'll eventually get some dirty bathwater. But NoSQL does solve real problems, and (to the point here) those are problems that are really difficult to predict that you'll need to solve from 15 years before now, because you need to know how the economics of buying computer hardware will change in the future. I don't think it is possible, at this point in the development of these technologies, to future-proof your skills if you want to work on new projects. You can either keep learning the new things, or waiting until other people find out which of the new things are actually going to last and then learn those things. You can use your current skills to maintain legacy systems. Or you can get into something like management, where you can leave specific technical details to other, younger people and focus on broader issues, like relations between your developers and the people they're serving.