What problems of distributed systems do you know and which patterns solve them?

The following problems are common in distributed systems:

• Data consistency: due to distribution and network delays, data may diverge. Patterns: Eventual Consistency, CQRS, Saga.
• Fault tolerance: nodes may fail or lose connection. Patterns: Circuit Breaker, Retry, Bulkhead.
• Synchronization and coordination: it is important to perform operations in a coordinated manner. Patterns: Leader Election, Distributed Locking (e.g., using Zookeeper or etcd).
• Handling network delays and failures: the network is unreliable, and timeouts are possible. Patterns: Timeouts, Fallback, Idempotency.
• Scalability: the system should grow efficiently. Patterns: Sharding, Load Balancing.
• Monitoring and tracing: it is difficult to track errors and performance. Patterns: Distributed Tracing (e.g., OpenTracing), Health Checks.

These patterns help build reliable, scalable, and manageable distributed systems.