Perplexity interview questions

Showing 1–13 of 13 results

• Design a CreditTracker with expirationsMedium

  This question evaluates a candidate's ability to design and implement data structures and algorithms for managing time-bound resources with non-monotonic (out-of-order) operations, emphasizing correctness and efficiency within the coding & algorithms domain.

  PerplexitySoftware EngineerCoding & AlgorithmsTechnical Screen
• Design a personal finance aggregatorHard

  This question evaluates skills in large-scale system design including API and third-party integrations, data ingestion and normalization, transactional consistency and idempotency, security and privacy controls, data modeling for multi-currency financial records, and operational concerns like alerts and budgeting.

  PerplexitySoftware EngineerSystem DesignTechnical Screen
• Design personalized discovery recommendationsMedium

  This problem evaluates your ability to design a scalable, real-time recommendation system that balances personalization with content discovery in an information-seeking environment.

  PerplexitySoftware EngineerML System DesignOnsite
• Design trending queries ranking systemMedium

  This question tests the ability to design a high-throughput, real-time pipeline that identifies and ranks trending search queries, requiring trade-offs between freshness, accuracy, and system latency.

  PerplexitySoftware EngineerML System DesignOnsite
• Diagnose overloaded Kubernetes clusterHard

  This question evaluates competency in diagnosing and mitigating production overloads in Kubernetes-based microservice architectures, emphasizing observability, autoscaling behavior, resource constraints, and incident-response reasoning.

  PerplexitySoftware EngineerSystem DesignTechnical Screen
• Implement Dependency-Aware To-Do ListMedium

  Design an in-memory task management system that tracks directed dependencies between tasks, prevents cycles, and unblocks dependent tasks upon completion.

  PerplexitySoftware EngineerCoding & AlgorithmsTechnical Screen
• Implement Stratified Sampling by CountryMedium

  Implement proportional stratified sampling on an in-memory list of records partitioned by a categorical key, ensuring exact sample size via the largest remainder method and reproducible selection.

  PerplexityData ScientistCoding & AlgorithmsTechnical Screen
• Implement Task Dependencies and FailureHard

  This question evaluates understanding of graph-based data structures and algorithms for modeling bidirectional task dependencies, status tracking, and efficient cascading failure propagation in an in-memory task manager.

  PerplexitySoftware EngineerCoding & AlgorithmsTechnical Screen
• Implement resilient LLM provider poolHard

  This English-language summary evaluates a candidate's ability to design a resilient, multi-provider LLM client library encompassing provider management, governance (rate limiting and quotas), resilience mechanisms (health checks, timeouts, circuit breakers), routing (cost- and latency-aware load balancing, retries and fallbacks), observability, security, and concurrency. Commonly asked in the ML System Design domain to assess architectural decision-making and trade-off reasoning for availability, cost, latency, and operational robustness, the question targets practical application and architectural-level thinking rather than purely conceptual or low-level implementation details.

  PerplexitySoftware EngineerML System DesignTechnical Screen
• Implement time-versioned KV store with restoreMedium

  This question evaluates a candidate's ability to design and implement a time-versioned key–value store, assessing knowledge of temporal data structures, versioning semantics, time-travel and range queries, deletion semantics, and rollback/restoration.

  PerplexitySoftware EngineerCoding & AlgorithmsOnline Assessment
• In-Memory File System: Add cd and Relative Path SupportMedium

  A multi-part coding exercise that builds an in-memory file system with directories, files and listings over absolute paths, then adds a cd command and relative path support to every operation. It tests tree data structures, path normalization with dot and dot-dot components, consistent error handling and safely refactoring earlier code.

  PerplexitySoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• In-Memory File System: Strict mkdir, touch, ls, rm, rmdir and a Command RunnerHard

  A two-part coding exercise to build an in-memory file system: first mkdir, touch and ls with strict path validation and no implicit creation of parent directories, then rm, rmdir and a function that executes command sequences. It tests tree modeling, error handling and working against provided tests.

  PerplexitySoftware EngineerSoftware Engineering FundamentalsOnsite
• Train and improve a scikit-learn binary classifierMedium

  This problem tests your proficiency in the scikit-learn workflow, specifically focusing on data preprocessing, addressing class imbalance in imbalanced datasets, and selecting appropriate metrics beyond accuracy.

  PerplexityMachine Learning EngineerMachine LearningTechnical Screen