InterviewStack.io LogoInterviewStack.io

CAP Theorem and Consistency Models Questions

Understand the CAP theorem and how Consistency, Availability, and Partition Tolerance interact in distributed systems. Know different consistency models including strong consistency such as linearizability, eventual consistency, causal consistency, and session consistency, and how to apply them to different use cases. Be familiar with consensus protocols and distributed coordination primitives such as Raft and Paxos, quorum reads and writes, two phase commit and when to use them. Understand trade offs between consistency and availability under network partitions, patterns for hybrid approaches where different data uses different guarantees, and the product and developer experience implications such as latency, stale reads, and API contract clarity.

HardTechnical
0 practiced
A datastore uses vector clocks and last-write-wins to resolve conflicts. Design a conflict-resolution system that reduces user-visible data loss by combining automatic merges for some data types (sets, counters) and human-assisted resolution for others. Discuss metadata, UI signals, and operational reconciliation strategies.
MediumTechnical
0 practiced
Design a monitoring and alerting scheme to detect consistency violations such as stale reads, write conflicts, and missed replication. Include synthetic and real-traffic checks, what metadata to collect, and alert thresholds that limit false positives.
HardTechnical
0 practiced
Design a developer SDK for a distributed key-value store that surfaces consistency guarantees (strong, causal, eventual). The SDK should provide primitives to request guarantees, helpers for migrations, testing utilities to simulate partitions, and instrumentation hooks. Describe key API shapes and developer ergonomics.
MediumTechnical
0 practiced
Microservices need to coordinate state changes across services without 2PC. Explain the Saga pattern (choreography and orchestration), show an example flow for an order checkout (reserve inventory, create payment, confirm order), and discuss failure/retry handling and eventual consistency concerns.
EasyTechnical
0 practiced
Compare linearizability and sequential consistency: define each guarantee in plain language, highlight the differences that matter for user-visible behavior (for example, in a document collaboration app), and give a simple example sequence of reads/writes where they yield different results.

Unlock Full Question Bank

Get access to hundreds of CAP Theorem and Consistency Models interview questions and detailed answers.

Sign in to Continue

Join thousands of developers preparing for their dream job.