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System Design Objective Questions and Answers - Set 3
This Java System Design quiz contains carefully curated objective questions with correct answers and clear explanations. It is designed for backend engineers, platform engineers, and architects to test your skills across scalable Java architectures, distributed systems, concurrency models, resiliency patterns, cloud-native deployments, and modern performance trade-offs. This is part 3 of the series.
Practice System Design MCQs with Detailed Explanations
Answer at least 12 questions to submit and verify answers.
31 Which approach best handles partial failures in Java service orchestration? High
Correct answer:
Saga pattern with compensations
Sagas manage long-running workflows with compensating actions for partial failures.
32 Which practice improves resiliency for downstream timeouts in Java HTTP clients? Medium
Correct answer:
Timeouts with retries and jitter
Timeouts with retries and jitter reduce coordinated retries and improve resilience.
33 Which storage strategy improves write amplification for log-structured workloads? High
Correct answer:
Log-structured merge design
Log-structured designs optimize write throughput for append-heavy workloads.
34 Which approach improves cache consistency for write-heavy Java services? High
Correct answer:
Write-through or write-behind with invalidation
Write-through or write-behind with invalidation reduces stale reads in write-heavy scenarios.
35 Which metric best indicates saturation in Java thread pools? Medium
Correct answer:
Queue depth and rejected executions
Queue depth and rejected tasks signal saturation and backpressure needs.
36 Which approach best isolates noisy neighbors in multi-tenant Java platforms? High
Correct answer:
Resource quotas and bulkheads per tenant
Bulkheads and quotas prevent one tenant from exhausting shared resources.
37 Which design reduces coupling between synchronous Java APIs and slow dependencies? Medium
Correct answer:
Async messaging with eventual processing
Async messaging decouples producers from slow consumers and improves system resilience.
38 Which pattern improves idempotency for HTTP POST in Java APIs? High
Correct answer:
Idempotency keys with deduplication store
Idempotency keys with a deduplication store prevent duplicate side effects on retries.
39 Which approach reduces hot-spotting in sharded Java data stores? High
Correct answer:
Randomized or hashed sharding keys
Hashed or randomized sharding keys distribute load more evenly and reduce hot spots.
40 Which JVM feature helps profile production latency without heavy overhead? High
Correct answer:
Low-overhead profiling and JFR sampling
Low-overhead profiling and sampling provide insights with minimal performance impact.
41 Which design best supports rolling back a faulty Java release quickly? Medium
Correct answer:
Immutable deployments with versioned artifacts
Immutable deployments with versioned artifacts enable fast rollback to known-good versions.
42 Which approach improves fairness under heavy contention in Java locks? High
Correct answer:
Fair ReentrantLock when fairness is required
Fair locks can improve fairness at the cost of some throughput under contention.
43 Which design reduces cross-service coupling for shared domain events in Java platforms? High
Correct answer:
Schema contracts with consumer-driven compatibility
Consumer-driven compatibility with schema contracts reduces coupling and enables independent evolution.
44 Which approach best mitigates retry storms in Java clients under partial outages? High
Correct answer:
Exponential backoff with jitter and circuit breakers
Backoff with jitter and circuit breakers prevents synchronized retry storms and protects dependencies.
45 Which architectural choice improves scalability for read-heavy leaderboards in Java backends? High
Correct answer:
Precomputed views with cache and read replicas
Precomputed views with caching and replicas optimize read-heavy access patterns at scale.