Creating an engaging conference isn't hard unless you're using the old model.
Why are we still doing conferences/meetings with the “sage on the stage” model, which pushes content at attendees, and why are we not creating opportunities for people to engage and interact in ways that create lasting movements for the kind of change we want to see?
Ask yourself if the purpose of your conference is to share content (sage on the stage) or is it to create an experience that is highly interactive, engaging and worthwhile in the moment, while also making an impact that lasts a lot longer than the duration of the conference.