This document describes the evolution of RTB House's real-time data processing architecture over five iterations. The first iteration used mutable data structures and single-datacenter processing. The second introduced Apache Kafka and data flow processing. The third moved to immutable event streams. The fourth added a multi-datacenter architecture with merged event streams. The current fifth iteration uses custom Kafka workers for higher distribution and tighter offset control. The changes have improved stability, scalability, data quality, and multi-region support for RTB House's growing real-time bidding platform.