Disaster Recovery Planning
How do you design a disaster recovery strategy? Explain RPO, RTO, and different DR approaches.
How do you design a disaster recovery strategy? Explain RPO, RTO, and different DR approaches.
RPO (Recovery Point Objective) is the maximum acceptable data loss measured in time - how much data can you afford to lose? RTO (Recovery Time Objective) is the maximum acceptable downtime - how quickly must you recover? DR strategies from cheapest to most expensive: Backup and Restore (high RPO/RTO, low cost), Pilot Light (minimal always-on resources), Warm Standby (scaled-down duplicate environment), and Multi-Site Active-Active (near-zero RPO/RTO, highest cost). Choose based on business requirements and criticality.
Disaster recovery is essential for business continuity. Senior engineers must understand the trade-offs between cost, complexity, and recovery capabilities. The right strategy depends on the cost of downtime versus the cost of redundancy.
DR Strategy Comparison
- Never testing the DR plan until a real disaster
- Not considering application-level DR, only infrastructure
- Underestimating the complexity of data consistency across regions
- How do you test your disaster recovery plan?
- What is the difference between disaster recovery and high availability?
- How do you handle data replication across regions for DR?
More Architecture interview questions
Also worth your time on this topic
System Design for Reliability
How would you design a highly available web application? What components and patterns would you use?
senior
High Availability Architecture Checklist
Comprehensive checklist for designing and implementing highly available systems with load balancing, failover, and redundancy.
90-120 minutes