[calenti]

You are going to learn a lot. Congratulations, leading a team in a hackathon can be an exhilarating, terrifying experience.

Create minimum (but not zero) formal communications and lots of informal routes with ways to find out information.

Slack is a great suggestion along with periodic all-team checkins/reports.

Set clear goals and a sense of mission, with open methods on how get there. As a leader, be involved and check in with team members to help clear roadblocks, connect resources and generally know where the team is at and their plans/progress/obstacles/workarounds is at any time.

A sprint model can work well, with a board of tasks and periodic checkins on process.