Many kinds of biases can derail careers. During her years as a tech-industry recruiter, Aline Lerner found firms ignored talented technologists if they lacked degrees from elite schools or experience with tech giants like Facebook Inc. She struggled to persuade startups to consider candidates who had gained skills through alternative routes, like online courses.

“The fact that they had these doors closed in their faces before they could show what they could do was extremely frustrating,” says Ms. Lerner. She quit recruiting to build Interviewing.io Inc., a website that pairs interviewers and interviewees in chat rooms where they are encouraged to talk but not share names. She’s considering adding a voice-masking feature for an extra layer of anonymity. So far, some startups and individuals at large companies are using the program, she says.