Organizing discussion groups in online conference I am organizing a math conference of about 70 people later this summer, and we have decided, in light of COVID-19, to make it an online conference. I would like to have opportunities for small discussion groups, such as naturally happen at coffee breaks, as well as having standard talks.

I am imagining having a wiki area of the conference website where people could indicate what they were interested in talking about when, so that other people could coordinate with them and plan a conference call. Has anyone done something like this? Does anyone have recommendations for software or for other ways to streamline this?
WAGON, the Western Algebraic Geometry ONline conference, had some interesting ideas in this direction. Here is a blogpost from one of the organizers about how it worked. Here is a twitter thread about some of the problems.