Ask HN: What are some great virtual event/conferences you've attended recently?

I am looking for a platform to host our company's annual event/conference.

The years previous, we've done very small group discussions and made it very interactive. And now we're faced with how to proceed with all of this going virtual.

Are there any cool virtual events that anyone has been to recently that is not just a series of presentation (Cisco webx-y)?

Also what platform was it on?

thank you!