The 10 testers versus 50,000 clickers framing is exactly how it happens in real life. One thing I would add for beginners, the fix is not learning every scaling tool, it is learning to ask one question early. What happens when everyone shows up at once. Work through a single flash sale scenario end to end, queue at the door, hold inventory with a TTL, shed the overflow politely, and you will understand more than a month of reading component lists. Your ticket site example is basically the Ticketmaster interview question wearing streetwear.