Inspired by the talk "You and Your Research" by Richard Hamming, I started wondering what are the important research topics on signal processing nowadays. Certainly an extensive list of topics would not be easy to find. I do not know the trending topics, for example, on Circuits and Systems, but I could imagine it for biomedical engineering.
So, in your opinion, what are some interesting research topics nowadays on signal processing? I could start with compressive sensing and tensor models.