Most of the teams I mentor before hackathons are in other cities, so the mentoring happens over calls squeezed between their build sprints. Remote mentoring fails when it is unstructured; it works when the team knows exactly when the mentor appears and what to bring.
Three fixed check-ins
Scoping call, before the event or in hour one. Twenty minutes. Output: one sentence for the problem, one for the user, one for the demo path, roles written down. I ask the scoping question until the team can answer it.
Midpoint call. Fifteen minutes of screen-share on the walking skeleton. I look for a real end-to-end path, however ugly, and for anything being built that is not on the demo path.
Mock pitch, two hours before freeze. The full three minutes with a timer, then Q&A using the questions judges ask, then one strength and one fix.
