In 2011, Soldsie co-founder Chris Bennett got an email from venture capital firm Andreessen Horowitz inviting him to a talk on leadership. When Mr. Bennett showed up, he was surprised that a large number of the people there shared his background: They were black and worked in the technology industry.

“I was just like, whoa, this is so cool,” he said. “It was just a diverse group.” Mr. Bennett, who has since attended several similar events hosted by the firm, said the events feel more authentic than “diversity” events hosted throughout the Valley by large tech companies. “It just makes it more comfortable,” he said.