Ask HN: What fields or technologies are you excited about?

My working hypthosis is that the software industry, and in particular SaaS, has seen immense growth and it's unlikely to see that kind of growth again. It's unlikely, but not totally impossible, to see the rise of something like Microsoft, Apple and Amazon again.

So, if you were at a stage of your career where you're trying to find interesting fields and industries that might see huge growth, where would you look?