Hunter Carter, 29, considers himself a “bootstrapper” and describes real estate as a calling. But he’s less interested in selling houses than he is in developing the systems that help his sales associates better assist clients. He’s spent the last few years building and refining a software platform called Auction Caddy that automates much of the sometimes arduous process of buying homes at auction. It tracks more than 200 data points to help investors evaluate which homes are a good bet and which they should avoid. The system seems to be working: Carter’s company sales over the past five years have totaled $100 million, and he’s adding a new agent roughly every two days. Eventually, he hopes to expand beyond the San Antonio market. He also has plans to turn Auction Caddy into its own company and roll the app out to the real estate community at large.