Character.AI, a rapidly growing AI platform, overcame its fragmented logging infrastructure by adopting a centralized observability stack built on ClickHouse and ClickStack, enabling efficient monitoring of its massive data scale. Mustafa Yildirim, the first Site Reliability Engineer at Character.AI, spearheaded the transition, which involved architectural decisions, schema optimizations, and ingestion strategies to handle over 450PB of log data monthly. This shift resulted in faster log search times, improved visibility, and significantly reduced costs. The implementation of ClickStack, following ClickHouse's acquisition of HyperDX, provided a modern user interface, fast query performance, and efficient data compression, allowing Character.AI to process 10 times more data while spending half the previous cost. By leveraging features like real-time log tailing, denoise, and pattern-based event grouping, the team enhanced root cause analysis and issue resolution. Looking forward, Character.AI plans to streamline its observability pipeline further by introducing a centralized gateway for log processing and integrating metrics into the same platform to enable comprehensive correlation and alerting capabilities.