I worked in telecom for a number of years. After years of outsourcing and cost cutting, I left and took a job at a company that might be considered fintech now. This coincided with the early days of electronic trading. This led to a software career in finance, which was an unanticipated but lucrative career turn.
I've had a similar experience transitioning from defense to fintech. The work is interesting and I found non-dog-eat-dog companies that still pay very well.