Ask HN: Security or fintech?

Right now, it's looking like I might have two options to choose from for internships this summer.

The first option is at a fintech company. From talking to others at my school who have interned there, including one of my friends who is now working there full-time, they sound like a great company to work for with an awesome culture. Every one of my interactions with anyone I've met from the company (including on-site) has been positive and left me feeling confident that the work environment there is going to be a good one.

I have an interview this week with a government contracting company that specializes in computer security. The internship is basically a training program for computer security, and we'll be going over reverse engineering, systems programming, and exploitation. I have been passionate about security and lower-level development since I was a kid, so this will be an incredibly tempting offer if things go well with the interview.

As far as career progression goes, I'm trying to get a feel for which one will offer the most opportunities and growth. My better half and I want to stay in the west, so any financial stuff in New York is off the table. If I go with the security option, I don't plan on staying in government contracting forever and want to eventually move to a different company to do research.

I am also interested in doing contracting on my own and possibly bootstrapping something further down the road. I feel like I'll get a more general development experience with the fintech option, but the security option will give me more specialized experience, and I'm not sure what is better if I want to pursue those goals.

I wanted to know what HN's thoughts are on the two industries. Does one have more potential for growth than the other? What are your experiences with each industry?