To achieve global scalability with Firebase, it is essential to configure multi-region settings for high availability and performance.Core Firebase services like Realtime Database and Cloud Firestore have single-region limitations by default.Strategies such as database replication, regional microservices, and data partitioning can enhance multi-region architecture.Steps include configuring Multi-Region Firestore, deploying Functions to multiple regions, and implementing regional routing.Performance optimization techniques for multi-region Firebase apps focus on data localization, connection optimization, and monitoring.Monitoring a multi-region Firebase app involves setting up alerts, tracking latency, and implementing failover strategies.Cost considerations for global deployments include managing data transfer fees, compute costs, and network traffic.Balancing performance, reliability, and cost is crucial for delivering a seamless global experience with Firebase applications.