1. A focus on discoverability. StackOverflow has set the bar on being able to find extremely specific results; could a similar experience be brought to course content?

2. A way to "layer on" complexity. I always find the early exercises overly simple; try to jump ahead; and then have to go back to try find where supporting info is addressed. Being able to navigate this explicitly. Start with a complex example; peel back the layers to underlying concepts - go up and down the levels over and over.

3. A platform which allows linking through all related topics. Similar to following articles in wikipedia - being able to start in a course on https://github.com/zio/zio and end up learning the relevant Category theory (I think; or whatever theory ZIO is build ontop of)

4. Always interactive and being able to immerse in real world ASAP. The jump between "exercise tasks" and "real world" often is large; but with environment support, and leveraging open source, the context of the lessons could be enriched.