There's a lot of problems that aren't being solved properly. For example, we've tried to integrate chat into our app recently and it was an absolute pain to the point we had to rewrite half the code because of the crazy latency on the servers, and hacking in some missing features.

Something like Framework7 is doing a good job of taking on Bootstrap or Ionic, but there's plenty of room there for improvement.

There's plenty of unicorns who could be doing a much better job - CRM, recipes, dating sites. I'd love to use a CRM but most of them are too complex, and you don't want to trust anything using vtiger with your critical business data.

Working on AI right now;

Gonna do a startup based around arguably the worst problem to have when trying to build a neural network from scratch;

Choosing the architecture of the net itself. It's super cumbersome, and you can often go days/weeks with crappy models by choosing poor architectures/objective functions.

Currently working on AI to build AI architecture recursively.