The process included a short phone interview with the manager, who gave me a "short" ("should take you no more than 3 hours") exercise. Then sent me a bunch of data without any explanations or headers for what this data actually was. I sent the results. Then the manager called to *scold* and *reprimand* me for the low quality of the results (his problem was that the classification model wasn't accurate enough). Any attempt to explain that this is the result of ~3-4 hours of work on senseless data made things worse. He started explaining to me how you "can't submit such a low quality result" and that his team "got better results in 2 days". What can I say - you sent this as a "3 hours exercise" - own up to it. Building features/exploration for senseless data is time consuming. I withdrew my application. The manager wanted to continue and wanted me to resubmit the exercise. I didn't. It was a bad experience having your not-yet-even-manager scold you about your work *and* completely ignore your answers.