ByteDance interview questions

Showing 1–30 of 160 results

• Add TTL to an LRU cacheHard

  This question evaluates a candidate's understanding of cache design, LRU eviction policies, time-to-live (TTL) semantics, appropriate data structures, time complexity reasoning, and concurrency control.

  ByteDanceSoftware EngineerSoftware Engineering FundamentalsOnsite
• Add Two Signed Decimal Character ArraysEasy

  This problem tests string manipulation, handling of sign logic, and carrying operations for large integer arithmetic without utilizing large integer libraries.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• Assess TikTok's ecosystemMedium

  Evaluate TikTok's ecosystem across viewers, creators, advertisers, and merchants. Covers ecosystem flywheel, strengths, weaknesses, 12-month strategic priorities, metrics, and platform tradeoffs.

  ByteDanceProduct ManagerProduct Design & StrategyTechnical Screen
• Assign Meetings and Find the Most-Used RoomHard

  Practice an interval-scheduling problem where meetings may be delayed and room-number tie rules affect the final count. The prompt tests precise simulation, large-input complexity, integer safety, and careful handling of simultaneous room availability.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• Backend Fundamentals Deep Dive: MySQL Internals, Redis, and the HTTP/HTTPS Request LifecycleHard

  This problem tests your depth in database durability mechanisms, caching strategies for consistency, and the network-level steps involved in secure HTTP request handling.

  ByteDanceBackend EngineerSoftware Engineering FundamentalsTechnical Screen
• Balance monetization with user experienceMedium

  Balance TikTok feed monetization with user experience by treating revenue as a multi-objective optimization problem. The answer covers ad load, relevance, pacing, creative quality, creator health, advertiser ROI, retention guardrails, segmented experiments, and rollback criteria.

  ByteDanceProduct ManagerProduct / Decision MakingTechnical Screen
• Build a Binary Tree from DescriptionsMedium

  This problem tests tree traversal, hash map utilization for parent-child relationship tracking, and identification of the root node in a graph-based structure.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• Build a Removable Timestamp-Ordered Task SchedulerMedium

  Design a task scheduler supporting task insertion/update, cancellation by ID, and retrieving ready tasks up to a given time limit using a min-heap with lazy deletion.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• Build a validated add-sub calculatorMedium

  This question evaluates skills in string parsing, tokenization, input validation, and safe integer arithmetic handling, with emphasis on enforcing format rules such as operator placement, prevention of leading zeros, and 32-bit signed integer bounds.

  ByteDanceSoftware EngineerCoding & AlgorithmsOnsite
• Build the Largest Allowed Number Below a LimitHard

  This problem tests greedy algorithm design, string-based numeric comparison, and backtracking/recursive state management to construct the largest possible number under a given limit.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• C++ vs Go for Backend Services: Memory, Concurrency and Trade-offsMedium

  From a TikTok backend intern interview: compare C++ and Go across memory management, concurrency, error handling, language features and tooling, and explain when each language is the better choice for a service. It tests practical understanding of runtime trade-offs rather than syntax trivia.

  ByteDanceSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• Calculate Triangle Probability From Broken StickMedium

  This question evaluates a candidate's understanding of geometric probability, continuous random variables, and spatial reasoning within probabilistic models.

  ByteDanceData ScientistStatistics & MathTechnical Screen
• Campaign Efficiency Metrics and Below-Average CTRMedium

  Practice a data scientist SQL interview question that calculates campaign cost and funnel rates, handles zero denominators, and filters campaigns against an average CTR benchmark. The exercise tests PostgreSQL date arithmetic, CTE organization, NULL-safe calculations, and deterministic output.

  ByteDanceData ScientistData Manipulation (SQL/Python)Technical Screen
• Check Whether Every Course Can Be Completed Under Prerequisite RulesMedium

  A graph feasibility problem: given n courses and pairs stating which course must be completed before another, decide whether every course can be finished. It tests modeling dependencies as a directed graph, recognizing circular requirements, and handling courses that fall into separate, disconnected groups.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• Check Whether an n x n Tic-Tac-Toe Game Is Over (Win or Draw)Medium

  Given an n x n tic-tac-toe board holding empty cells and two players' marks, decide whether the game is over because one player occupies an entire row, column or diagonal, or because the board is full with no winner. It tests complete line checks, draw detection and edge cases such as all-empty lines and a 1 x 1 board.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• Choose Between REST, WebSocket, and Server-Sent Events for an Agent RuntimeMedium

  This question tests the ability to evaluate communication protocols based on specific architectural requirements, including bidirectional signaling, state recovery, and infrastructure overhead.

  ByteDanceSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• Choose Components for a Data WarehouseMedium

  This question tests the ability to distinguish between distributed data processing frameworks, storage engines, and relational databases, evaluating your understanding of trade-offs in large-scale data infrastructure.

  ByteDanceData EngineerSoftware Engineering FundamentalsHR Screen
• Choose Precision, Recall, or F1 for Agent EvaluationMedium

  This question tests the ability to map business objectives and error costs to appropriate classification metrics in a real-world system context.

  ByteDanceSoftware EngineerMachine LearningTechnical Screen
• Choose Ranking Functions, Customer Value Metrics, and Predictive ModelsMedium

  This problem tests the ability to implement SQL window functions for cohort analysis, define robust customer lifetime value metrics, and articulate the trade-offs between various machine learning algorithms in a production setting.

  ByteDanceData ScientistMachine LearningTechnical Screen
• Clockwise Spiral Traversal of a Matrix With O(1) Extra Space and No MutationMedium

  From a TikTok backend intern interview: return the elements of an m x n matrix in clockwise spiral order using only constant extra space beyond the output, without a visited marker and without modifying the matrix. It tests careful traversal logic and off-by-one handling when a single row or column remains.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• Combined Median of Two Sorted Integer Lists in Logarithmic TimeHard

  From a ByteDance technical screen for a machine learning engineer role: given two sorted integer arrays, return the median of all their elements combined, averaging the two middle values when the total count is even. It tests reasoning about sorted order under a logarithmic time target and edge cases such as an empty array.

  ByteDanceMachine Learning EngineerCoding & AlgorithmsTechnical Screen
• Compare SQL counts, windows, and NULL semanticsMedium

  This question evaluates understanding of SQL aggregation and NULL semantics, window functions (ROW_NUMBER vs RANK), join behavior to avoid double-counting, and defensive handling of NULLs and divide-by-zero using COALESCE and NULLIF in a data manipulation context.

  ByteDanceData ScientistData Manipulation (SQL/Python)Technical Screen
• Compute Minimum Parentheses AdditionsMedium

  This question evaluates proficiency in string processing and algorithmic reasoning for balancing parentheses, testing understanding of invariants and edge-case handling.

  ByteDanceData ScientistCoding & AlgorithmsTechnical Screen
• Compute Sentence SimilarityMedium

  This question evaluates understanding of sentence-level and token-level embedding techniques, text preprocessing, similarity metrics, edge-case handling for empty or unknown tokens, and trade-offs between pretrained sentence encoders and averaged word embeddings.

  ByteDanceMachine Learning EngineerMachine LearningTechnical Screen
• Compute root-to-leaf number sumMedium

  This problem tests your ability to perform depth-first search on a binary tree and maintain state (the current path sum) during the traversal to compute a cumulative total.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen
• Connect Points With Minimum Total DistanceMedium

  This problem tests your ability to model a geometric optimization task as a Minimum Spanning Tree (MST) problem and implement it efficiently using Kruskal's or Prim's algorithm.

  ByteDanceData EngineerCoding & AlgorithmsOnsite
• Count House Segments After Sequential DemolitionsMedium

  Track the number of consecutive house segments after each requested demolition on an integer line. Each removal can eliminate an isolated segment, trim an endpoint, or split a run, so the solution must update the count efficiently across many distinct positions.

  ByteDanceSoftware EngineerCoding & AlgorithmsOnline Assessment
• Count Numbers with an Even Number of DigitsMedium

  Count how many positive integers in an array have an even number of decimal digits. Respect ordinary representations without leading zeroes, count repeated values independently, and handle boundaries such as 10 and 10000 correctly.

  ByteDanceSoftware EngineerCoding & AlgorithmsOnline Assessment
• Count Same-Day Registered PostersMedium

  This question evaluates SQL querying skills, including joining relational tables, date handling, aggregation, and deduplicating users across events. Commonly asked in Coding & Algorithms interviews for data scientists, it assesses practical relational database querying and analytics tasks—filtering, grouping, and counting distinct users across tables—and tests practical application of SQL rather than purely conceptual database theory; this summary is in English.

  ByteDanceData ScientistCoding & AlgorithmsTechnical Screen
• Count Similar Photo GroupsMedium

  This question evaluates understanding of graph connectivity and equivalence relations, requiring recognition of connected components from an adjacency-matrix representation of pairwise similarity.

  ByteDanceSoftware EngineerCoding & AlgorithmsTechnical Screen