VueJS
I got to learn VueJS as a great technology to implement API driven frontends in a very structured, maintainable and scalable way. Further decoupling frontend logic and user focused functionality makes a lot of sense to keep software projects maintainable, and VueJS provides a very mature framework to realise this. However, as always, some changes can be seen already on the horison, new technologies further utilising web-sockets being a very promising example.