Interactively exploring Reddit posts using basic Scala in the browser

Author here. I'd appreciate your feedback on this article that builds off a series of articles teaching basic Scala. I'm particularly trying to create materials to teach basic Scala to non-engineers (chiefly data scientists) because I've found Scala to be a powerful language for my data science and analysis work. The goal of the educational series is to build up to using Scala in Spark within a managed Hadoop cluster (e.g., Databricks).

In this post, I'm trying to use exercises that I think will be more interesting and engaging than just showing off the language. What do you think? Is analyzing Redditors interesting to you? Do you have any thoughts for other datasets that would be even more interesting for people to work with while learning Scala?

In general, I'd appreciate any critical feedback because I'm looking to get better at developing such educational resources.

Thanks for your time!