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Software Engineer Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
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Showing 5311–5340 of 5874 results
- The Trade DeskMediumSoftware EngineerImplement a Cloud Storage Service
This question evaluates a candidate's ability to implement an in-memory cloud storage system, exercising skills in data structures and stateful API design, string handling and pattern matching, sorting and eviction algorithms, and per-user resource accounting.
Coding & AlgorithmsOnline Assessment - TikTokMediumSoftware EngineerAnswer common behavioral questions using STAR
This question assesses the candidate's ability to communicate past professional experiences using the STAR method, focusing on accountability, problem-solving, and collaboration in a high-pressure environment.
Behavioral & LeadershipTechnical ScreenCommunicationSTAR MethodConflict Resolution - TikTokMediumSoftware EngineerAnswer core Python, CS, DB, and testing questions
This problem tests foundational software engineering knowledge across Python internals, database indexing, and testing strategy through a multi-part conceptual assessment.
Software Engineering FundamentalsTechnical ScreenPythonDatabasesSystems Design - TikTokMediumSoftware EngineerCompute length of longest increasing subsequence
This question evaluates understanding of subsequences, dynamic programming and algorithmic optimization for array processing, and is categorized under Coding & Algorithms; it emphasizes practical application of algorithm design and complexity analysis rather than purely theoretical knowledge.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerCompute pipeline order from dependencies
This question evaluates understanding of graph algorithms and dependency resolution, specifically topological sorting and cycle detection, along with competence in choosing appropriate data structures and analyzing time/space complexity.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerCount deletions making array fair
This question evaluates proficiency with array manipulation, parity-aware summation, and combinatorial counting when elements are removed, situating it in the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerCount distinct island shapes in a grid
This problem tests grid traversal (DFS/BFS) and the ability to represent spatial structures in a canonical form to identify unique patterns.
Coding & AlgorithmsTechnical ScreenDFSGraphGrid - TikTokMediumSoftware EngineerCount islands on a torus grid
This question evaluates skills in graph and grid algorithms, topology-aware adjacency (torus wrap-around), and maintaining dynamic connectivity under incremental updates.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerDelete nodes in linked list and binary tree
This question evaluates proficiency in mutable data structure operations, specifically linked list node removal and binary tree node replacement/deletion, requiring knowledge of traversal, pointer/reference manipulation, and edge-case handling.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerDescribe a project you are proud of
This question evaluates technical leadership, ownership, system design, execution, collaboration, trade-off reasoning, and the ability to demonstrate measurable impact from a software project.
Behavioral & LeadershipTechnical Screen - TikTokMediumSoftware EngineerDescribe a service performance challenge
This question evaluates competency in production performance engineering, observability-driven diagnosis, experimentation and impact quantification, as well as leadership in prioritizing trade-offs and risk mitigation.
Behavioral & LeadershipTechnical Screen - TikTokMediumSoftware EngineerDescribe career plan and teamwork approach
This question evaluates a candidate's career planning, self-awareness, and teamwork competencies, specifically goal setting, alignment with team priorities, conflict resolution, and collaborative decision-making.
Behavioral & LeadershipTechnical Screen - TikTokMediumSoftware EngineerDescribe toughest challenge and resolution
This question evaluates a candidate's problem-solving, leadership, communication, decision-making, and ability to quantify impact when resolving complex technical or organizational challenges.
Behavioral & LeadershipTechnical Screen - TikTokMediumSoftware EngineerDesign LRU cache with O(1) operations
This question evaluates a candidate's understanding of data structures and algorithm design, specifically skills in implementing constant-time cache operations, eviction policies, update handling, and concurrency/thread-safety considerations.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerDesign a distributed key-value store
This problem tests your ability to design a scalable, fault-tolerant distributed key-value store, focusing on partitioning strategies, replication, and handling node failures.
System DesignTechnical ScreenDistributed SystemsScalabilityHashing - TikTokHardSoftware EngineerDesign a high-concurrency ticketing system
TikTok software-engineer system-design interview question: design a high-concurrency ticketing / flash-sale system that survives millions of concurrent purchase attempts with zero oversell. It tests admission control and fairness (virtual waiting room, FIFO vs lottery), atomic inventory allocation with TTL reservations, anti-bot defenses, idempotent order creation, hot-key sharding, the data model and APIs, caching, message queues and delivery semantics, consistency and reconciliation, failure handling, capacity planning, SLOs, load testing, and monitoring.
System DesignTechnical Screen - TikTokHardSoftware EngineerDesign and explain your project architecture
A TikTok software-engineer system-design screen that asks you to walk through one of your recent projects end-to-end: architecture diagram, components and data stores, sync vs. async data flows and protocols, scaling and capacity planning, fault tolerance, backpressure, idempotency, observability, and security. It also probes the design trade-offs you made, the real failure modes you hit, the measurable impact, and what you would redesign. Includes a fully worked reference answer plus the scoring rubric.
System DesignTechnical Screen - TikTokEasySoftware EngineerDesign automated regression tests for an API
This question assesses the ability to structure a comprehensive automated regression suite for a RESTful API, focusing on test case selection, validation strategies, and maintenance.
Software Engineering FundamentalsTechnical ScreenAPIQACI/CD - TikTokMediumSoftware EngineerDesign low-latency large-scale hotel booking system
This question evaluates understanding of large-scale backend and distributed system design, including scalability, high availability, consistency models, concurrency control to prevent double-booking, hotspot mitigation, and protocol trade-offs for low-latency booking and availability flows.
System DesignTechnical Screen - TikTokHardSoftware EngineerDesign overload protection with load shedding
Design overload protection with load shedding evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - TikTokMediumSoftware EngineerDesign system to detect privacy-leak records
This question evaluates a candidate's ability to design scalable ML-driven systems for detecting and classifying privacy-sensitive and PII-containing records across structured and unstructured data, testing competencies in data engineering, machine learning (including deep learning and LLM/RAG integrations), system architecture, and privacy/security considerations. It is commonly asked to probe reasoning about functional and non-functional requirements, trade-offs in detection and classification approaches, evaluation metrics like precision and recall, feedback loops and operational scaling, and it falls under ML system design with a practical, application-level focus rather than purely conceptual abstraction.
ML System DesignTechnical Screen - TikTokHardSoftware EngineerDesign tables from metrics
This question evaluates analytics data modeling and event-driven warehousing skills, including schema design, metric derivation, partitioning/clustering strategies, and data-quality concerns such as deduplication, late arrivals, and idempotency.
System DesignTechnical Screen - TikTokMediumSoftware EngineerDiscuss Python mutability, copying, and GIL
This question evaluates understanding of Python mutability and copying semantics — including how mutable versus immutable objects affect function arguments and container behavior — and knowledge of the Global Interpreter Lock (GIL) and concurrency models.
Data Manipulation (SQL/Python)Technical Screen - TikTokMediumSoftware EngineerExplain C++ containers, segfaults, and virtual dispatch
This question assesses the candidate's deep understanding of C++ memory management, the runtime implementation of polymorphism, and the performance characteristics of standard containers.
Software Engineering FundamentalsTechnical ScreenC++Memory ManagementPolymorphism - TikTokMediumSoftware EngineerExplain DPO and construct its training data
This question evaluates understanding of Direct Preference Optimization (DPO) for fine-tuning large language models, assessing conceptual differences from PPO-based RLHF and the competency to design pairwise preference training datasets.
Machine LearningTechnical Screen - TikTokMediumSoftware EngineerExplain Java ConcurrentHashMap and queues
This question evaluates a candidate's understanding of Java concurrency primitives and concurrent collection implementations, focusing on thread-safety, synchronization mechanisms, lock-free techniques, and blocking versus non-blocking queue behavior.
Software Engineering FundamentalsTechnical Screen - TikTokMediumSoftware EngineerExplain Java DI, AOP, and transactions
This question evaluates understanding of Java framework internals and related competencies including dependency injection, aspect-oriented programming and proxy mechanisms, transaction management, annotation processing, bean lifecycle, classpath scanning, bean scopes, and circular dependency detection or resolution.
Coding & AlgorithmsTechnical Screen - TikTokHardSoftware EngineerExplain SRE architecture and troubleshooting scenarios
This question evaluates a candidate's competency in SRE architecture and reliability engineering, covering Kubernetes fundamentals, pod failure troubleshooting, SLO/SLA/SLI reasoning, multi-layer latency diagnosis, and SQL versus NoSQL trade-offs within the System Design domain.
System DesignTechnical Screen - TikTokEasySoftware EngineerExplain TLS Handshakes and HTTPS Traffic Inspection
Tests understanding of the TLS handshake, asymmetric vs. symmetric cryptography in HTTPS, certificate authority verification, and the mechanics of forward secrecy versus intercepting HTTPS proxies.
Software Engineering FundamentalsTechnical ScreenNetworkingSecurityTLS/SSL - TikTokHardSoftware EngineerExplain Your System Architecture
Explain Your System Architecture evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
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