Question

Design the system that decides which thumbnail/title artwork to show for each piece of content on a streaming homepage. New titles arrive constantly with no engagement data, you have dozens of artwork variants per title, and you want to converge fast on the best variant per title while not wasting too many impressions on bad variants — and you must avoid permanently locking in a variant that only looked good early by chance. Design the online optimization system and contrast it with running a fixed A/B test per title.