This must depend a lot on the place. I did a data science take-home that asked you to scrape some documents from the web, group them by topic, extract some inf

This must depend a lot on the place. I did a data science take-home that asked you to scrape some documents from the web, group them by topic, extract some information the clusters, and visualize it. This could be a few hours of work, or an entire research career. IMO, a good take-home needs to be aggressively scoped. Ideally, I think you'd explicitly ask for --and expect--a "bare minimum" solution and a list of potential improvements. That list would be great fodder for in-person interviews too.