"Assignments" from potential employers in Language Tech - is this normal?

Context: I come from a linguistics background and have several years of experience in my specialty within the field. I passed the first round of interviews for an EdTech learning company for a high-ish level role. They gave me an "assignment" to see how I would handle what I assume are issues they are facing regarding scoring, mapping of scores, comparisons, etc. The assignment has multiple parts and I have been explicitly asked for all of my thinking regarding my choices--whys, why nots, deep explanations, etc. Essentially, they want me to show all of my steps. I'm not even halfway done, and