The text discusses common challenges faced by fantasy sports and live events app builders, along with design patterns that can help solve these problems. These challenges include distributing data to an unknown number of players in real-time (solved using the Publish/Subscribe pattern), maintaining consistent data synchronization across devices (addressed through serial JSON patches and CRDT), and handling upstream game play events from user devices (resolved with message queues). The author, CEO of Ably, a realtime data delivery platform, shares their insights and experiences in addressing these issues.