Re Dorin Ioniţă (Also a longer write-up Sergey Zelvenskiy's post) Whenever people asked me about AI winter. I couldn't help but think of on-line poker in 2008 and web programming in 2000. But let me just focus on web-programming?
At around 1995-2001, there was the time people keep on telling you "web programming" is the future. Many young people were told that if you know html and CGI programming, you would have a bright future. That's not too untrue. In fact, if you get good at web programming at 2000, you probably started a company and made a decent living for .... 3-4 years. But then competition arises, many college starts to include web as a core curriculum - as a result, web programming is sort of a very common skills nowadays. I am not saying it is not useful - but you are usually competing with 100 programmers to get one job.
So back to AI. Since we start to realize AI/DL can be useful, now everyone is jumping onto the wagon. Of course, there are more senior people who has been 'there', joined couple of DARPA projects or worked in ML startup years before deep learning. But most of them are frankly young college kids, who try to have a future with AI/DL. (Check out our forum?) For them, I am afraid it's likely that they will encounter a future similar to web programmers in 2000. The supply of labor will one day surpass the demand. So it's very likely that data science/machine learning is not their final destination.
So am I arguing there is an AI winter coming? Not in the old classical sense of "AI Winter" when research funding dried up. But more on like AI as a product in a product cycle - just like every technology - it will go through a hype cycle. And one day when the reality of the product doesn't meet expectation, things would just bust. It's just the way it is. We can argue to the death on whether deep learning is different or not. But you should know every technology follow similar hype cycle. Some last longer, some don't. We will have to wait and see.
For OP: If you are asking of a career advice though, so here is something I learn from poker (tl;dr story) and many other things in life - if you are genuinely smart, you can always learn up a new topic quicker than other people. That's usually what determine if you can make a living. The rest are luck, karma and whether you buy beers for your friends.