It may be that your thesis topic is far removed from practical applications, but you likely have a strong enough foundation in math that you would be great at working on a lot domain specific applications. Some others mentioned machine learning, and this is likely a good option, but only one of many. Spin this around and think of it from the business side. Where are there opportunities to put more robust analytical solutions in place in the business world? Start thinking about every company you see, buy products from, or otherwise interact with - how could they (or are they) be more effective at what they do with better math? Everything from better sales forecasting at your local supermarket, to better car design.