When Nneka Obiekwe started a WhatsApp group chat in September, she was just trying to help her out-of-work friends.

A consultant and skilled networker, Ms. Obiekwe, 37, is the kind of person friends turn to when they are looking for a referral or connection to a hiring manager. But since March, she had been receiving pleas every few weeks. By autumn, her network was tapped out.

Most of the people reaching out were, like Ms. Obiekwe, Black women, and she started to feel that they needed a community as much as referrals. She created the WhatsApp chat, called Black Women Rising, and posted the link to it on Threads.

Within 24 hours, more than 500 people joined. Most were midcareer or senior professionals who had been laid off in the previous few months.

Ms. Obiekwe moved the group to Discord, a messaging platform that could better organize the 500 or so daily messages people were sending in channels with names like “Share Your Good News” or “Vent Among Friends.” MORE