Backend interview prep

Start

Solution Architect Database Interview Questions (Top 100 Questions with Answers)

Master Solution Architect Database Interview Questions covering enterprise database architecture, cloud-native databases, scalability, distributed systems, CAP theorem, replication, sharding, disaster recovery, security, migration strategies, and real-world architecture decisions.

Introduction

Database interviews for Solution Architects are very different from developer interviews.

Interviewers expect you to think about

  • Enterprise Architecture
  • Scalability
  • High Availability
  • Cloud Architecture
  • Disaster Recovery
  • Performance
  • Security
  • Cost Optimization
  • Business Tradeoffs

Instead of asking

What is an Index?

they ask

How would you design a global banking database serving 100 million customers?

This guide contains the Top 100 Solution Architect Database Interview Questions asked in companies like

  • Amazon
  • Google
  • Microsoft
  • IBM
  • Oracle
  • Salesforce
  • Adobe
  • Walmart
  • JPMorgan Chase
  • Capital One

Solution Architect Roadmap

Business Requirements
         │
         ▼
Functional Design
         │
         ▼
Database Selection
         │
         ▼
Architecture Design
         │
         ▼
Scalability
         │
         ▼
Availability
         │
         ▼
Security
         │
         ▼
Disaster Recovery
         │
         ▼
Cost Optimization

Requirement Gathering

1. How do you begin a database architecture discussion?

Start with

  • Functional Requirements
  • Non-Functional Requirements
  • Data Growth
  • Users
  • Traffic
  • Budget

2. Which non-functional requirements matter most?

  • Availability
  • Scalability
  • Security
  • Latency
  • Throughput
  • Compliance
  • Cost

3. Why estimate traffic first?

Because database design depends on

  • Requests/sec
  • Reads
  • Writes
  • Storage
  • Growth

4. What questions should you ask?

  • Daily Users?
  • Peak TPS?
  • Global Users?
  • SLA?
  • Recovery Time?

5. Why are business requirements important?

Architecture should solve business problems instead of only technical problems.

Database Selection

6. SQL vs NoSQL?

SQL NoSQL
ACID Flexible Schema
Complex Queries Massive Scale
Strong Consistency Horizontal Scaling

7. PostgreSQL vs Oracle?

Oracle

Enterprise Features.

PostgreSQL

Lower Cost

Open Source.

8. MongoDB vs Cassandra?

MongoDB

Flexible Documents.

Cassandra

Massive Write Scalability.

9. DynamoDB vs Aurora?

DynamoDB

Serverless NoSQL.

Aurora

Managed Relational Database.

10. Redis use cases?

  • Cache
  • Sessions
  • Rate Limiting
  • Leaderboards

Architecture Design

11. Explain Polyglot Persistence.

Different databases for different workloads.

Example

  • PostgreSQL → Orders
  • Redis → Cache
  • MongoDB → Catalog
  • DynamoDB → Sessions

12. Monolithic Database vs Database per Service?

Microservices generally prefer Database per Service to reduce coupling.

13. Shared Database challenges?

  • Tight Coupling
  • Deployment Issues
  • Scaling Problems

14. Why separate OLTP and OLAP?

Different workloads require different optimization strategies.

15. What is CQRS?

Separate Read Model

and

Write Model.

Scalability

16. Vertical Scaling?

Increase CPU

RAM

Storage.

17. Horizontal Scaling?

Add More Servers.

18. When should databases be sharded?

Only after

  • Query Optimization
  • Replication
  • Caching

are no longer sufficient.

19. Best shard key?

  • High Cardinality
  • Even Distribution

20. Hot Partition?

One partition receives most traffic.

High Availability

21. How do you design HA?

  • Replication
  • Automatic Failover
  • Monitoring

22. Primary-Replica?

Single Writer.

Multiple Readers.

23. Multi-Primary?

Multiple Writers.

Conflict Resolution required.

24. Active-Active?

Multiple writable regions.

25. Active-Passive?

Standby activated during failures.

Disaster Recovery

26. Disaster Recovery Components?

  • Backup
  • Replication
  • Monitoring
  • Recovery Testing

27. RPO?

Recovery Point Objective.

28. RTO?

Recovery Time Objective.

29. PITR?

Point-in-Time Recovery.

30. Cross-Region Replication?

Protects against regional failures.

CAP Theorem

31. Explain CAP Theorem.

Consistency

Availability

Partition Tolerance.

32. Banking System?

Prioritize Consistency.

33. Social Media?

Availability often has higher priority.

34. Cassandra?

AP

with Tunable Consistency.

35. DynamoDB?

Availability

Partition Tolerance.

Transactions

36. Distributed Transactions?

Saga Pattern.

37. Two Phase Commit?

Strong consistency

Higher latency.

38. Outbox Pattern?

Reliable Event Publishing.

39. Event Sourcing?

Store events

instead of state.

40. CDC?

Capture database changes.

Cloud Databases

41. Aurora?

Cloud-native relational database.

42. DynamoDB?

Serverless NoSQL.

43. Cosmos DB?

Global NoSQL.

44. Cloud Spanner?

Globally consistent relational database.

45. Azure SQL?

Managed SQL Server.

46. Google Cloud SQL?

Managed relational database.

47. Serverless Database?

Automatic compute scaling.

48. Multi-Cloud Strategy?

Avoid vendor lock-in where business requirements demand portability.

49. Hybrid Cloud?

On-Premises

Cloud.

50. Database Migration?

Plan

Validate

Rollback.

Security

51. Encryption?

At Rest

and

In Transit.

52. IAM?

Authentication.

53. RBAC?

Role-Based Access.

54. Secrets Management?

AWS Secrets Manager

Azure Key Vault

HashiCorp Vault.

55. Database Auditing?

Mandatory for regulated industries.

56. Data Masking?

Protect sensitive information.

57. Tokenization?

Replace sensitive values with tokens.

58. Compliance?

PCI DSS

HIPAA

GDPR

SOC 2.

59. Network Security?

Private Networks

Firewalls

VPC.

60. Zero Trust?

Verify every request.

Performance

61. Query Optimization?

Execution Plans.

62. Index Strategy?

Based on access patterns.

63. Connection Pooling?

Reuse connections.

64. Read Scaling?

Read Replicas.

65. Write Scaling?

Partitioning

Sharding.

66. Cache Strategy?

Redis.

67. Materialized Views?

Pre-computed reports.

68. Compression?

Reduce storage costs.

69. Archiving?

Move historical data.

70. Database Observability?

Logs

Metrics

Tracing.

Enterprise Scenarios

71. Design Banking Platform.

  • PostgreSQL
  • Redis
  • Kafka
  • Audit

72. Design E-Commerce.

  • Product Catalog
  • Orders
  • Inventory
  • Search

73. Design Netflix.

  • Metadata
  • Watch History
  • Recommendations

74. Design Uber.

  • Geo Queries
  • Driver Matching
  • Tracking

75. Design WhatsApp.

  • Messaging
  • Offline Queue
  • Delivery Status

76. Design Hospital System.

  • Patients
  • Doctors
  • Billing

77. Design Airline Reservation.

Prevent

Double Booking.

78. Design Fraud Detection.

Real-Time Processing

Cache

Streaming.

79. Design Payment Gateway.

Idempotency

Transactions

Retries.

80. Design Audit Platform.

Immutable Logs.

Leadership Questions

81. How do you perform Architecture Reviews?

Review

  • Security
  • Scalability
  • Performance
  • Cost
  • Availability

82. How do you reduce cloud costs?

  • Right Sizing
  • Auto Scaling
  • Reserved Capacity
  • Storage Lifecycle Policies

83. Capacity Planning?

Estimate

Growth

Traffic

Storage.

84. Technology Selection?

Choose technology based on requirements, operational complexity, team expertise, and long-term maintainability.

85. Production Readiness Checklist?

  • Backup
  • Monitoring
  • Alerts
  • Security
  • Load Testing

Solution Architect Questions

86. Design for one billion users.

Use

  • CDN
  • Cache
  • Replication
  • Sharding

87. Handle one million TPS.

Kafka

Redis

Distributed Databases.

88. Multi-Tenant Database?

  • Shared Schema
  • Separate Schema
  • Separate Database

89. Zero Downtime Migration?

Dual Writes

CDC

Validation.

90. Blue-Green Deployment?

Zero Downtime Release.

91. How would you migrate Oracle to PostgreSQL?

  • Assessment
  • Schema Conversion
  • Data Migration
  • Validation
  • Cutover
  • Rollback

92. Design Global Database.

Multi-Region

Geo Routing

Replication.

93. Design Disaster Recovery.

Primary Region

↓

Secondary Region

↓

Backup

↓

Recovery Automation.

94. How do you monitor databases?

  • CloudWatch
  • Prometheus
  • Grafana
  • Datadog
  • Splunk

95. Database SLA?

Availability

Performance

Recovery.

96. Database Cost Optimization?

  • Storage Tiering
  • Reserved Instances
  • Auto Scaling
  • Archiving

97. Most common architecture mistakes?

  • Wrong Database Selection
  • Poor Partition Key
  • Missing Indexes
  • No Monitoring
  • No Backup Strategy

98. Enterprise Database Checklist?

  • Security
  • HA
  • DR
  • Monitoring
  • Scaling
  • Cost

99. What do interviewers expect?

  • Architecture Thinking
  • Tradeoff Analysis
  • Business Alignment
  • Leadership
  • Communication

100. What makes an excellent Solution Architect?

  • Strong Technical Foundation
  • Business Understanding
  • Cloud Expertise
  • Excellent Communication
  • Real Production Experience
  • Leadership
  • Decision Making

Enterprise Database Architecture

                     Global Users
                          │
                   Global DNS / CDN
                          │
                 Global Load Balancer
                          │
          ┌───────────────┴───────────────┐
          ▼                               ▼
    Application Region A           Application Region B
          │                               │
          └───────────────┬───────────────┘
                          ▼
                     Redis Cluster
                          │
            ┌─────────────┴─────────────┐
            ▼                           ▼
     Read Replica                 Read Replica
            │                           │
            └─────────────┬─────────────┘
                          ▼
                 Primary Database Cluster
                          │
          ┌───────────────┴───────────────┐
          ▼                               ▼
       CDC/Kafka                  Backup Storage
          │                               │
          ▼                               ▼
  Analytics Platform         Disaster Recovery Region

Database Selection Matrix

Requirement Recommended Database
Banking PostgreSQL / Oracle
Payments PostgreSQL / Aurora
Shopping Cart DynamoDB
Product Catalog MongoDB
Cache Redis
Session Store Redis
IoT Cassandra / DynamoDB
Event Store Cassandra
Search Elasticsearch / OpenSearch
Analytics Snowflake / Redshift / BigQuery
Audit Logs PostgreSQL + Object Storage

Architecture Decision Checklist

Before finalizing a database architecture, verify:

  • Business requirements are clear.
  • Read/write traffic is estimated.
  • Database selection matches workload.
  • Schema supports future growth.
  • Indexes match access patterns.
  • Caching strategy is defined.
  • Replication and failover are planned.
  • Backup and disaster recovery are tested.
  • Monitoring and alerting are configured.
  • Security and compliance are addressed.
  • Cost optimization opportunities are identified.

Quick Revision

Topic Key Focus
Database Selection SQL vs NoSQL
Scalability Sharding
High Availability Replication
Disaster Recovery RPO & RTO
Transactions Saga
Integration CDC & Outbox
Performance Caching
Security Encryption & IAM
Cloud Aurora, DynamoDB
Leadership Tradeoff Analysis

Interview Tips

Solution Architect interviews evaluate how you make decisions, not just what technologies you know.

When answering:

  • Start with business requirements.
  • Estimate scale before choosing technologies.
  • Explain tradeoffs for every architectural decision.
  • Discuss scalability, availability, security, observability, and cost together.
  • Mention backup, disaster recovery, and compliance where appropriate.
  • Draw simple architecture diagrams.
  • Show how the architecture can evolve as the business grows.

Summary

Solution Architect Database interviews assess your ability to design enterprise-grade, cloud-native database platforms that are scalable, secure, highly available, and cost-effective. Success requires deep understanding of database selection, distributed systems, cloud databases, replication, sharding, security, performance, observability, disaster recovery, and architecture tradeoffs.

Mastering these 100 Solution Architect Database Interview Questions prepares you for Solution Architect, Principal Engineer, Enterprise Architect, Cloud Architect, Staff Engineer, and Technical Architect roles.