When you're at a hackathon, you tend to use the tools that you know. That way you can put all of your effort and time into the app you're trying to build, and not into having to learn a new tool that might set you back.
But what if you want to use ArcGIS but don't have much experience with it?
Well, here's a video that in just 30 minutes will give you everything you need to get going and get productive with ArcGIS Online for hosting data, making maps, and making apps. Even during a fast-paced hackathon you may find giving 24 minutes to see what these tools can do for you could be a great investment when you see what kinds of capabilities you can bring to your project.
In this video, we cover all 10 of these topics:
Here is a link to the video: https://tiny.cc/ArcGISHacksVideo
(ed. on 2021-03-21 to update info and links)