Oso's system architecture is designed for high reliability and resilience, with a focus on ensuring seamless authorization processes for its customers. Utilizing a cell-based architecture, each Oso instance operates alongside a local SQLite database, minimizing network latency and external dependencies. This setup allows for quick scalability in response to traffic spikes and maintains system availability, achieving over 99.99% uptime as monitored from October 21, 2024, to October 21, 2025. The write process employs a global Kafka cluster to handle high write volumes while maintaining data consistency, though at the cost of increased baseline write latency. In case of network outages or application issues, Oso provides a failover mechanism through a local Fallback cluster that syncs data every 30 minutes to ensure continuity. The system's performance is continuously monitored and optimized, with authorization query latencies consistently maintained under 10ms. These architectural decisions are guided by the need to prevent disruptions and maintain customer trust, with ongoing improvements driven by customer feedback and detailed performance monitoring.