Personalization is another of those education buzzwords that sounds positive, but can mean so many different things. There is nothing necessarily wrong with recognizing that adapting to individual students interests and needs, but the reality is that advocates who are proponents of some types of personalization object to others.
Audrey Watters does a great job of explaining the variety of ways in which learning can be personalized and the role technology can play in many of these opportunities. I encourage your attention to this extensive review.
My personal interest has long been in the individualization of the expected speed of learning. Simply put, traditional learning offers instruction at narrowly fixed rate. There are learners who could move faster to learn more and there are learners who cannot keep up and gradually find themselves lack the necessary existing knowledge for the new skills and knowledge they are expected to acquire. A tutor would probably be the best way to respond, but the cost is prohibitive. Technology offers an alternative (think Kahn Academy as an example) that offers promise.