How would you design a system to ensure data consistency across microservices in a distributed environment? Please discuss patterns you might employ and the challenges you expect to encounter.

## Approach Begin with fundamentals of distributed systems, discuss specific design patterns, and elaborate on trade-offs between consistency and availability. ## Complexity **Time:** O(1) for individual operations, O(n) for complex transactions **Space:** O(n) for event storage and management. ## Trade-offs - Eventual consistency could lead to stale reads, but improves scalability and resilience.