PHP 7 is a massive upgrade in terms of performance and stability and Rasmus is keen to see developers make the switch. I will highlight some of the key points that were covered in this talk many of which I use myself to promote upgrading to PHP 7.
Do you have a WordPress website that is turning into a pain to manage? It may be because you have poor plugin management. Plugins in WordPress are meant to make your life easier but if they incorrectly managed they can create the opposite result.