Assess graduate students' ability to analyze scalability, consistency, and fault‑tolerance trade-offs among Paxos, Raft, and Byzantine Fault Tolerant protocols in geo‑distributed systems. Scope: quorum and leader-election strategies, safety vs liveness under WAN latency and network partitions, performance and replication costs, crash vs Byzantine failure models, and mitigation patterns (hierarchical consensus, sharding, hybrid approaches). Tasks: compare protocol behavior in defined fault/latency scenarios, quantify trade-offs using metrics, and justify design choices for given requirements.