2015 has inherited a lot of trends from previous years, there’s been a steady evolution of ideas — Flat Design into Material Design for example — but nothing as revolutionary as Responsive Design.
However, we are starting to see trends that feel fresh, either through new treatments or because they’re genuinely new ways of approaching old problems. The most widespread of these so far, has been the use of patterns in web design.
Patterns serve a variety of purposes, from communicating a brand value, to adding motion to an interface, to enlivening the simple blocks of color that flat design favors. And the use of patterns, although not scientifically categorizable, falls into one of five broad and inter-related categories…
See some great examples of Designing patterns: the biggest web trend of 2015 so far