Well, we’ve certainly got people moving towards Single Page Apps + Lambda/API-GW on the backend. Its becoming more and more of a pattern. Not to mention mobile applications typically powered by an API fit as well. The benefits are numerous and people are reaping said benefits.
When you say “complex event based app” I guess I’m still looking for an example. Overall across the industry I still see people trying to break apart their more complex applications into smaller services. It’s still very early days for this as an architectural pattern in enterprises though. Things like AWS Step Functions can also help with complex event processing and we see this cropping up too. Azure has Logic Apps which is similar(-ish? I’m not terribly deep in it).
I guess our definitions of “persistent process” just aren’t the same. If I need an always running process/daemon of some sort that’s a fairly solved problem in the industry. For serverless the overall availability of the platform is persistence of the process, with user/process data stored on something purpose built or handled by something like Step Functions.
I’m biased by definition of my role, but given past “lives” I’m feeling strongly the FaaS/event driven model is the future of application design. Not sure if you coming to re:Invent in a few weeks, but if you ever wanted a better view on this I’m here in NY and happy to talk about it :)