In my own experience, it is true that a portfolio really helps you stand out. Recruiters often ask for your GitHub profile or blog.
However, I've found that recruiting really differs based on studio size. Indies tend to take what the can get, often forming a ragtag team of people with various levels of education and experience. AAA studios, on the other hand, are very discerning when it comes to programmers. They often won't give you a chance unless you either have solid experience or a university degree from a university they know is up to par. That's because there are so many talented programmers who really want to work in AAA