The fourth chapter is small triumphs and larger risks. A pilot customer ran the build in a production shard and reported a 7% drop in latency and a 12% increase in throughput—numbers that made spreadsheets glow. Traffic increased, but so did scrutiny. The feature that surfaced those telemetry patterns also exposed internal timing jitters that, under adversarial conditions, could be exploited. Security raised a flag. The product manager convened a war room. The team did what teams do under pressure: prioritized, patched, and documented, turning the contractor’s shrug into explicit invariants and tests.