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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 1801–1830 of 9403 results
- ByteDanceMediumSoftware EngineerDetect a Pythagorean Triple in an Integer Array
This problem tests the ability to optimize a brute-force approach into an efficient search using sorting and the two-pointer technique to satisfy a geometric condition.
Coding & AlgorithmsOnsiteArraysTwo PointersSorting - ByteDanceMediumData ScientistDetermine Whether an Integer Is a Palindrome
This problem tests your ability to manipulate integers mathematically to detect palindromic sequences without converting the number into a string, requiring careful handling of edge cases and integer overflow.
Coding & AlgorithmsTechnical ScreenMathAlgorithmsInteger Manipulation - ByteDanceHardSite Reliability EngineerDetermine whether squares can fit
This question evaluates spatial reasoning, combinatorial packing, and constraint-satisfaction skills in the context of placing integer-aligned squares within an m x n rectangle.
Coding & AlgorithmsTechnical Screen - ByteDanceMediumData ScientistDiagnose Low CTR in an Advertising Campaign Funnel
Prepare for a product analytics interview by diagnosing below-average advertising CTR from limited campaign-level funnel metrics. The question tests metric interpretation, uncertainty, evidence-versus-hypothesis discipline, and how to plan useful follow-up analysis.
Analytics & ExperimentationTechnical Screen - ByteDanceMediumData ScientistDiscuss Your Data Analytics and Causal-Inference Experience
Practice describing data analytics and causal-inference experience while separating descriptive insights from credible intervention effects.
Behavioral & LeadershipTechnical Screen - ByteDanceMediumSoftware EngineerElasticsearch Deep Dive: Index Mapping Design and How the Inverted Index Works
From a TikTok backend intern interview: explain how the Elasticsearch index and field mappings in a resume project were designed and why, then explain how an inverted index works. It tests whether a candidate understands the search technology they list, from mapping trade-offs to how queries are answered.
Software Engineering FundamentalsTechnical Screen - ByteDanceMediumSoftware EngineerElements Occurring More Than n/3 Times in a Sorted Array
This problem tests your ability to optimize frequency counting in a sorted array by leveraging binary search to achieve logarithmic time complexity, rather than a linear scan.
Coding & AlgorithmsTechnical ScreenBinary SearchArraysSorting - ByteDanceMediumSoftware EngineerEnumerate All Simple Directed Cycles
This problem tests graph traversal skills, specifically the ability to identify unique simple cycles in a directed graph using canonical representations to avoid duplicates.
Coding & AlgorithmsTechnical ScreenGraphsDFSBacktracking - ByteDanceMediumSoftware EngineerEnumerate All Simple Directed Paths
This problem tests graph traversal techniques, specifically depth-first search (DFS) with backtracking to identify all unique simple paths in a directed graph.
Coding & AlgorithmsTechnical ScreenGraphDFSBacktracking - ByteDanceEasySoftware EngineerEqualize Root-to-Leaf Sums in an N-ary Tree
Find the minimum total increments needed to make every root-to-leaf path in a nonnegative-valued N-ary tree have the same sum. The parent-array input may contain 200,000 nodes and a depth beyond Python's recursion limit.
Coding & AlgorithmsTechnical Screen - ByteDanceMediumSoftware EngineerEvaluate a Migration from MySQL to MongoDB
Evaluate whether a MySQL-backed service should migrate to MongoDB using its actual workload and correctness needs. Compare relational and document models, joins and transactions, then outline a dual-run migration, rollback plan, and measurements that would prove an improvement.
System DesignTechnical Screen - ByteDanceMediumSoftware EngineerEvaluate an Integer Arithmetic Expression with Parentheses
This problem tests the ability to evaluate arithmetic expressions containing addition, subtraction, multiplication, and division, while correctly handling parentheses, operator precedence, and unary operators without using recursion.
Coding & AlgorithmsTechnical ScreenStackMathParsing - ByteDanceHardBackend EngineerExplain Backend Fundamentals and AI Tooling
This question tests foundational knowledge across systems engineering, database design, version control, and modern AI integration strategies.
Software Engineering FundamentalsHR ScreenSystems DesignDatabasesGit - ByteDanceMediumSoftware EngineerExplain Backend Infrastructure Fundamentals
This question tests your understanding of Kafka's distributed messaging architecture, specifically how message distribution, ordering guarantees, and consumer scalability interact during consumer group operations.
Software Engineering FundamentalsTechnical ScreenKafkaDistributed SystemsMessaging - ByteDanceMediumSoftware EngineerExplain CAP, indexing, locks, and logs
This question tests fundamental knowledge of distributed systems theory, database storage structures, concurrency control, and recovery mechanisms.
Software Engineering FundamentalsTechnical ScreenDistributed SystemsDatabasesConcurrency - ByteDanceMediumSoftware EngineerExplain Composite and Covering Indexes in MySQL
This question tests the understanding of MySQL B-tree index structures, specifically how composite index ordering affects query performance, selectivity, and disk I/O.
Software Engineering FundamentalsTechnical ScreenMySQLDatabaseB-Tree - ByteDanceMediumApplied ScientistExplain GRPO for LLM Reinforcement Learning and How It Differs from PPO
An ML question asking you to explain Group Relative Policy Optimization (GRPO) for fine-tuning large language models with reinforcement learning. It tests your grasp of group-normalized advantages, the clipped objective with a KL penalty, the contrast with PPO and its value model, and common failure modes.
Machine LearningTechnical Screen - ByteDanceMediumSoftware EngineerExplain Kafka and Message-Queue Delivery Semantics
This question tests your understanding of distributed messaging patterns, focusing on the architectural differences between log-based and queue-based systems and the trade-offs involved in ensuring reliable message delivery.
Software Engineering FundamentalsTechnical ScreenKafkaDistributed SystemsMessage Queues - ByteDanceMediumMachine Learning EngineerExplain LLM generational improvements, multimodal LLMs, and normalization in LLMs
Three conceptual LLM questions: the main improvements across generations of a model family as described in technical reports, how multimodal image-and-text models are built and trained, and why modern LLMs use layer normalization or RMSNorm with pre-norm placement instead of batch normalization.
Machine LearningTechnical Screen - ByteDanceMediumData ScientistExplain Type I/II errors vs precision/recall
This question evaluates understanding of Type I and Type II errors in hypothesis testing and binary classification, their correspondence to false positives and false negatives, and how those concepts relate to precision and recall within the Statistics & Math domain.
Statistics & MathTechnical Screen - ByteDanceMediumSoftware EngineerExplain Virtual Memory Beyond Physical RAM
This question tests the conceptual understanding of how an operating system abstracts memory management through virtual address spaces, demand paging, and hardware-assisted translation.
Software Engineering FundamentalsTechnical ScreenOperating SystemsMemory ManagementPaging - ByteDanceMediumSoftware EngineerExplain Why You Want to Change Roles
This question assesses the candidate's professional maturity, self-awareness, and ability to frame career transitions as proactive pursuits of growth rather than reactions to negative past experiences.
Behavioral & LeadershipOnsiteBehavioralCareer GrowthCommunication - ByteDanceMediumMachine Learning EngineerExplain XGBoost's Overfitting Resistance
This question evaluates understanding of ensemble learning and model generalization, focusing on why gradient-boosted tree ensembles are often less prone to overfitting than single decision trees.
Machine LearningTechnical Screen - ByteDanceMediumSoftware EngineerExplain a Project's Implementation and Design Decisions
This question assesses a candidate's ability to communicate complex technical work, justify architectural trade-offs, and reflect critically on their own engineering process.
Behavioral & LeadershipTechnical ScreenArchitectureProblem SolvingCommunication - ByteDanceMediumSoftware EngineerExplain a promotion and key project impact
This question evaluates a candidate's ability to communicate career progression, leadership influence, ownership of high-impact projects, and aptitude for articulating measurable outcomes and trade-offs.
Behavioral & LeadershipTechnical Screen - ByteDanceMediumSoftware EngineerExplain the TCP Three-Way Handshake and Its Guarantees
Tests in-depth understanding of the TCP three-way handshake, state transitions, sequence/acknowledgment arithmetic, and failure modes such as dropped final ACKs.
Software Engineering FundamentalsTechnical ScreenNetworkingTCP/IPOperating Systems - ByteDanceMediumData ScientistFind Each User's Earliest Seven-Day Activity Streak
Tests your ability to identify consecutive date sequences (gaps-and-islands problem) in PostgreSQL, aggregate streaks, and filter for each user's earliest qualifying period.
Data Manipulation (SQL/Python)Technical Screensqlpostgresqlwindow-functions - ByteDanceMediumSoftware EngineerFind Maximum Candies With Two Types
This question evaluates algorithmic problem-solving with arrays, focusing on managing constraints on the number of distinct element types in a contiguous sequence and maintaining element frequency/state during a traversal.
Coding & AlgorithmsOnsite - ByteDanceEasySoftware EngineerFind Missing Ranges with Bounds
This question evaluates understanding of sorted array manipulation, interval arithmetic, detection of maximal missing ranges, and careful handling of boundary and edge cases in integer intervals.
Coding & AlgorithmsTechnical Screen - ByteDanceHardSoftware EngineerFind Unique One-Use Combination Sums with Negative Values
Tests backtracking and branch-and-bound optimization when searching for subsets that sum to a target with duplicate and negative values.
Coding & AlgorithmsTechnical ScreenBacktrackingBranch and BoundArray