I finished my PhD in Algebraic Geometry/Number Theory in 2013, and made the decision not to apply for postdocs: very few of my fellow students had found academic positions I had the feeling the unless you're a superstar/potential-Fields-medalist (which I'm not) it's very hard to build a career as a pure mathematician. Also I don't think it's fair on my wife and her career to ask her to move cities every few years while I'm doing postdocs ... and it looks like this is a common requirement for early career researchers these days.
So I've been working as a Data Scientist for the past 3 years, and I'm really hating the feeling of working in the business/corporate world ... it all feels so short-term and meaningless, and I also miss the intellectual challenge of pure research.
This leads to my question. I'm thinking about applying for some postdocs with the aim of going back into academia. My dilemma is do I try and find something in a "pure" field that I feel excited about, like algebraic geometry, representation theory, string theory or quantum computing? Or should I apply for something I don't feel so passionate about but that's currently more well-funded, and that builds on my skills from my work in industry, like genomics, computer vision or speech recognition ... will my passion grow as I go deeper into the field?
I want to be realistic and responsible about my career/life choices, but I also don't want to get stuck doing something I don't care about.
I know it's a bit of a vague question, but I would love to hear if anyone's had a similar experience.