Learners enrol, work through a curriculum, sit quizzes and earn certificates; coupons discount the price and reviews build the sales page. The demo ships as Northlight Academy — seven courses across eighteen modules, with enrolments at every stage from just-started to certified. Marking is one pure function shared by the tests, the submission and every later re-display of a score, so a learner can never be shown two different marks for the same attempt. Scores are basis points, not floats — a 66.67% pass mark is stored as 6667, and nobody compares decimals to decide who passed. No partial credit on "select all that apply", deliberately: half of a multi-select is a wrong answer.