Most engineering blogs that talk about Kafka either quote the Netflix case study or walk you through the "hello world" producer-consumer example. Both are useless if you're actually trying to decide whether to adopt Kafka for a product that might hit a million users — or stay at ten thousand forever. This is a story from the trenches of building Cricket Winner, a real-time cricket scores, news, and opinion-trading platform for the Indian market. I'll walk through the decisions we made, the decisions we got wrong, and the numbers we wish someone had shared with us when we started. The Product, in One Paragraph Cricket Winner does three things in real time: it streams live ball-by-ball updates during matches, pushes breaking cricket news as it happens, and runs an opinion-trading engine where users take positions on outcomes ("Will Kohli score a fifty this innings?"). During an India vs.…