practice a little every day, paws crossed ♡
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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 841–870 of 4616 results
- BridgeMediumSoftware EngineerSelect an Object by a Dynamic Integer Field
Implement a clean, defensive utility function to select a dictionary from a collection based on the minimum or maximum value of a dynamic integer field, properly handling missing keys and ties.
Software Engineering FundamentalsTechnical Screendata-manipulationpythonclean-code - BridgeMediumSoftware EngineerSolve path normalization and nested iterator
This question evaluates proficiency in string/path normalization, manipulation of hierarchical data structures, stack-based iterator design, lazy versus eager flattening strategies, and algorithmic time/space complexity analysis in the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - ByteDanceEasySoftware EngineerAdd Two Signed Decimal Character Arrays
This problem tests string manipulation, handling of sign logic, and carrying operations for large integer arithmetic without utilizing large integer libraries.
Coding & AlgorithmsTechnical ScreenStringsMathTwo Pointers - ByteDanceMediumProduct ManagerAssess TikTok's ecosystem
Evaluate TikTok's ecosystem across viewers, creators, advertisers, and merchants. Covers ecosystem flywheel, strengths, weaknesses, 12-month strategic priorities, metrics, and platform tradeoffs.
Product Design & StrategyTechnical Screen - ByteDanceHardSoftware EngineerAssign Meetings and Find the Most-Used Room
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.
Coding & AlgorithmsTechnical Screen - ByteDanceHardBackend EngineerBackend Fundamentals Deep Dive: MySQL Internals, Redis, and the HTTP/HTTPS Request Lifecycle
This problem tests your depth in database durability mechanisms, caching strategies for consistency, and the network-level steps involved in secure HTTP request handling.
Software Engineering FundamentalsTechnical ScreenMySQLRedisSystem Design - ByteDanceMediumProduct ManagerBalance monetization with user experience
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.
Product / Decision MakingTechnical Screen - ByteDanceMediumSoftware EngineerBuild a Binary Tree from Descriptions
This problem tests tree traversal, hash map utilization for parent-child relationship tracking, and identification of the root node in a graph-based structure.
Coding & AlgorithmsTechnical ScreenTreesHash MapGraph - ByteDanceMediumSoftware EngineerBuild a Removable Timestamp-Ordered Task Scheduler
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.
Coding & AlgorithmsTechnical Screenheaphash-tabledesign - ByteDanceHardSoftware EngineerBuild the Largest Allowed Number Below a Limit
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.
Coding & AlgorithmsTechnical ScreenGreedyStringsRecursion - ByteDanceMediumSoftware EngineerC++ vs Go for Backend Services: Memory, Concurrency and Trade-offs
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.
Software Engineering FundamentalsTechnical Screen - ByteDanceMediumData ScientistCalculate Triangle Probability From Broken Stick
This question evaluates a candidate's understanding of geometric probability, continuous random variables, and spatial reasoning within probabilistic models.
Statistics & MathTechnical Screen - ByteDanceMediumData ScientistCampaign Efficiency Metrics and Below-Average CTR
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.
Data Manipulation (SQL/Python)Technical Screen - ByteDanceMediumSoftware EngineerCheck Whether Every Course Can Be Completed Under Prerequisite Rules
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.
Coding & AlgorithmsTechnical Screen - ByteDanceMediumSoftware EngineerCheck Whether an n x n Tic-Tac-Toe Game Is Over (Win or Draw)
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.
Coding & AlgorithmsTechnical Screen - ByteDanceMediumSoftware EngineerChoose Between REST, WebSocket, and Server-Sent Events for an Agent Runtime
This question tests the ability to evaluate communication protocols based on specific architectural requirements, including bidirectional signaling, state recovery, and infrastructure overhead.
Software Engineering FundamentalsTechnical ScreenSystem DesignProtocolsAPI Design - ByteDanceMediumSoftware EngineerChoose Precision, Recall, or F1 for Agent Evaluation
This question tests the ability to map business objectives and error costs to appropriate classification metrics in a real-world system context.
Machine LearningTechnical ScreenMetricsClassificationModel Evaluation - ByteDanceMediumData ScientistChoose Ranking Functions, Customer Value Metrics, and Predictive Models
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.
Machine LearningTechnical ScreenSQLCustomer-AnalyticsModel-Selection - ByteDanceMediumSoftware EngineerClockwise Spiral Traversal of a Matrix With O(1) Extra Space and No Mutation
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.
Coding & AlgorithmsTechnical Screen - ByteDanceHardMachine Learning EngineerCombined Median of Two Sorted Integer Lists in Logarithmic Time
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.
Coding & AlgorithmsTechnical Screen - ByteDanceMediumData ScientistCompare SQL counts, windows, and NULL semantics
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.
Data Manipulation (SQL/Python)Technical Screen - ByteDanceMediumData ScientistCompute Minimum Parentheses Additions
This question evaluates proficiency in string processing and algorithmic reasoning for balancing parentheses, testing understanding of invariants and edge-case handling.
Coding & AlgorithmsTechnical Screen - ByteDanceMediumMachine Learning EngineerCompute Sentence Similarity
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.
Machine LearningTechnical Screen - ByteDanceMediumSoftware EngineerCompute root-to-leaf number sum
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.
Coding & AlgorithmsTechnical ScreenTreesDFSRecursion - ByteDanceMediumData ScientistCount Same-Day Registered Posters
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.
Coding & AlgorithmsTechnical Screen - ByteDanceMediumSoftware EngineerCount Similar Photo Groups
This question evaluates understanding of graph connectivity and equivalence relations, requiring recognition of connected components from an adjacency-matrix representation of pairwise similarity.
Coding & AlgorithmsTechnical Screen - ByteDanceHardSoftware EngineerCount Target-Sum Paths in an N-ary Tree
This problem tests the ability to navigate tree structures and use hash maps to track cumulative path sums efficiently, specifically in the context of an N-ary tree.
Coding & AlgorithmsTechnical ScreenTreesDFSPrefix Sum - ByteDanceMediumSoftware EngineerDefend a Project's Schema, Indexes, and Concurrency Model
Practice defending a database design by connecting schema choices, indexes, consistency behavior, and concurrency controls to concrete access patterns. The solution explains how to reason about CAP trade-offs, lost-update prevention, transaction boundaries, and the operational cost of each index.
Software Engineering FundamentalsTechnical Screen - ByteDanceEasySoftware EngineerDescribe Over-Engineering and UX Wins
This question evaluates engineering judgment, trade-off analysis, and product-oriented UX skills by probing examples of over-engineering and measurable user-experience improvements.
Behavioral & LeadershipTechnical Screen - ByteDanceMediumProduct ManagerDescribe your key projects and impact
Prepare TikTok platform PM behavioral deep-dive answers for self-introduction, successful projects, ownership, difficulties, scale, strengths, weaknesses, job changes, and team fit. The solution emphasizes STAR storytelling, platform impact, metrics, and positive motivation.
Behavioral & LeadershipTechnical Screen