Database Selection and Trade Offs Questions

How to evaluate and choose data storage systems and architectures based on workload characteristics and business constraints. Coverage includes differences between relational and nonrelational families such as document stores, key value stores, wide column stores, graph databases, time series databases, and search engines; mapping query patterns and latency requirements to storage options; trade offs between strong consistency and eventual consistency and their impact on availability and complexity; partition key design, replication strategies, and high availability considerations; operational concerns including backups, monitoring, vendor and cost trade offs, migration or hybrid strategies, and when to adopt polyglot persistence. Senior level discussion includes selecting specific managed services and reasoning about expected load patterns, failure modes, and operational burden.

MediumTechnical

37 practiced

Describe how to perform capacity planning for a new database supporting a media streaming service with projected growth: start at 1M users, 10k concurrent streams, expected 3x growth in 18 months. What factors (IOPS, storage, CPU, memory, networking) do you model, and how do you plan headroom and scaling steps?

HardSystem Design

43 practiced

Design a consistent strategy for primary key and secondary index placement in a distributed key-value store that supports replica reads. Explain how you would route reads and writes, and how to handle stale reads from replicas while providing options for stronger consistency when required.

MediumTechnical

43 practiced

You notice write latency to your DB increases dramatically at peak traffic. Describe an investigation checklist (operational runbook) to diagnose whether the problem is due to database indexes, locks/contention, I/O saturation, network issues, or an application-level hot-spot. Include monitoring metrics and sample queries to run.

MediumTechnical

36 practiced

Write a brief migration plan to move an application from MySQL to Amazon DynamoDB for a read-heavy leaderboard feature. Include steps for data export/import, handling foreign-key-like relationships, ensuring zero-downtime reads, and eventual rollback strategy.

HardTechnical

37 practiced

Describe a migration strategy to move from a single PostgreSQL monolith to a microservices architecture where different services need different storage models (e.g., one needs a graph DB, another needs a time-series DB). Discuss data synchronization, cutover plans, backward compatibility, and incremental migration techniques.

Unlock Full Question Bank

Get access to hundreds of Database Selection and Trade Offs interview questions and detailed answers.

Join thousands of developers preparing for their dream job.