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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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 4081–4110 of 4616 results
- TikTokHardData ScientistExplain and tune XGBoost; prevent overfitting
This question evaluates understanding of XGBoost tree-boosting internals, hyperparameter impacts on bias/variance/training time, strategies for imbalanced binary classification and leakage-aware validation, post-training calibration, and interpretability for tabular fraud detection.
Machine LearningTechnical Screen - TikTokMediumSoftware EngineerExplain gap and project contributions
This question evaluates a candidate's ability to explain employment gaps and provide a project deep-dive demonstrating ownership, technical decision-making, measurable impact, and clear delineation of personal contributions, testing communication, accountability, and system design competencies.
Behavioral & LeadershipTechnical Screen - TikTokEasySoftware EngineerExplain motivation for QA and career goals
This question evaluates a candidate's career motivation, communication and leadership competencies alongside technical troubleshooting and QA/testing role fit by probing short- and mid‑term goals, reasons for graduate study, and rationale for pursuing QA versus other engineering tracks.
Behavioral & LeadershipTechnical Screen - TikTokMediumMachine Learning EngineerExplain your VLM project end-to-end
This question evaluates proficiency in vision-language model engineering, including model architecture (vision encoder, language model, fusion), data curation and distribution, training recipes, evaluation metrics, inference latency, and limitations analysis within the Machine Learning domain of multimodal/Vision-Language models.
Machine LearningTechnical Screen - TikTokMediumData ScientistExplain your most impactful project trade-offs
This question evaluates a data scientist's leadership, stakeholder management, quantitative impact measurement, trade-off analysis, risk mitigation, and conflict-resolution skills within end-to-end project work.
Behavioral & LeadershipTechnical Screen - TikTokMediumSoftware EngineerFind a valid course order from prerequisites
This problem tests your ability to model dependencies as a directed graph and determine a valid sequence using topological sorting (Kahn's algorithm or DFS).
Coding & AlgorithmsTechnical ScreenGraphTopological SortDFS - TikTokMediumMachine Learning EngineerFind and count target-sum subarrays
Find and count target-sum subarrays evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokEasySoftware EngineerFind first and last index of target
This question evaluates mastery of searching algorithms and algorithmic complexity analysis, particularly the ability to locate boundary positions within a sorted array.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerFind kth smallest in sorted 2D matrix
This question evaluates algorithmic problem-solving and data-structure reasoning, focusing on order statistics and operations on a row- and column-sorted matrix within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - TikTokMediumMachine Learning EngineerFind length of longest common subsequence
This problem tests your ability to identify overlapping subproblems and optimal substructure by implementing a dynamic programming solution to find the length of the Longest Common Subsequence (LCS) between two strings.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingStringsOptimization - TikTokHardSoftware EngineerFind longest substring with ≥k repeats
This problem tests your ability to use the sliding window technique combined with frequency maps to find the longest substring containing characters that each appear at least k times.
Coding & AlgorithmsTechnical ScreenStringsSliding WindowTwo Pointers - TikTokEasySoftware EngineerFind start indices of anagram substrings
This question evaluates proficiency in string processing, frequency-based pattern matching, and algorithmic efficiency under length constraints, testing the ability to reason about time and space trade-offs for substring searches.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerFind the Longest Substring with at Most Two Distinct Characters
Tests the ability to use the sliding window technique combined with a hash map to maintain a dynamic character set and determine the maximum length of a valid substring in linear time.
Coding & AlgorithmsTechnical Screensliding-windowhash-tabletwo-pointers - TikTokEasyData ScientistFind top-paid employee per department
This question evaluates a candidate's competency in SQL data manipulation, including aggregation, ranking, handling of duplicate and historical rows, tie semantics, and temporal data interpretation when determining the top-paid employee per department.
Data Manipulation (SQL/Python)Technical Screen - TikTokMediumMachine Learning EngineerFix a BST with two misplaced keys
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Fix a BST with two misplaced keys states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerFlatten object & Promise.all
This question evaluates proficiency in JavaScript data manipulation and asynchronous programming, testing competencies in transforming nested objects into single-level key paths and reproducing Promise.all semantics.
Coding & AlgorithmsTechnical Screen - TikTokHardMachine Learning EngineerGenerate all safe queen placements on board
This question evaluates algorithm design for constraint-satisfaction problems, testing skills in search, recursion, backtracking, combinatorics, and state-space pruning.
Coding & AlgorithmsTechnical Screen - TikTokEasySoftware EngineerGive a Technical Research-Project Deep Dive
Tests your ability to communicate complex technical research clearly, delineate your specific personal contributions, explain rigorous experimental design, and critically evaluate limitations and next steps.
Behavioral & LeadershipTechnical ScreenResearchTechnical Deep DiveProject Walkthrough - TikTokMediumSoftware EngineerHandle disorganized interview logistics
This question evaluates a candidate's communication, initiative, and stakeholder-management competencies in coordinating interview logistics for a Software Engineer role.
Behavioral & LeadershipTechnical Screen - TikTokEasyData ScientistHow do you choose a classification threshold?
This question evaluates a data scientist's competency in binary classification threshold selection, end-to-end ML pipeline design, model evaluation, and operational trade-offs including class imbalance, asymmetric error costs, and limited escalation capacity, within the Machine Learning domain of model evaluation and deployment.
Machine LearningTechnical Screen - TikTokEasyData ScientistHow would you measure misinformation impact and recommendation bias?
This question tests the ability to design an evaluation framework for identifying algorithmic bias and measuring the reach of misinformation within a content recommendation system.
Analytics & ExperimentationTechnical ScreenAnalyticsRecommendation SystemsMetrics - TikTokMediumData ScientistIdentify Repeat Advertisers from Consecutive Weeks
This question evaluates a candidate's proficiency in manipulating relational data to identify recurring entities across consecutive time periods, focusing on SQL/Python data manipulation and temporal comparison of records.
Data Manipulation (SQL/Python)Technical Screen - TikTokMediumData ScientistImplement K-means and run two iterations
This question evaluates understanding of k-means clustering concepts (k-means++ initialization, Lloyd iterations, and SSE) and proficiency in numerical implementation and vectorized array operations.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerImplement O(1) randomized multiset
Implement O(1) randomized multiset evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - TikTokMediumSoftware EngineerImplement a match-3 board resolver
TikTok software-engineer technical-screen coding question: implement a match-3 board resolver over an m×n grid. Repeatedly remove connected horizontal/vertical runs of three or more equal cells, apply gravity so survivors fall and blanks rise to the top, cascade until the board is stable, and return the final board plus the total cells removed. It tests grid simulation, run detection via linear scans, per-column gravity, termination reasoning, and time/space complexity analysis.
Coding & AlgorithmsTechnical Screen - TikTokEasySoftware EngineerImplement an LRU cache
This question tests the ability to implement a Least Recently Used (LRU) cache using a combination of a hash map and a doubly linked list to achieve constant time complexity for core operations.
Coding & AlgorithmsTechnical ScreenHash MapLinked ListDesign - TikTokMediumSoftware EngineerImplement and compare key design patterns
Implement and compare key design patterns 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.
Software Engineering FundamentalsTechnical Screen - TikTokMediumSoftware EngineerImplement binary tree in-order traversal
This question evaluates understanding of binary tree traversal, comparing recursive and iterative (explicit stack) implementations and their time and space complexity. Commonly asked in Coding & Algorithms interviews to assess both practical implementation and conceptual understanding of tree data structures, algorithmic trade-offs, and complexity analysis.
Coding & AlgorithmsTechnical Screen - TikTokHardSoftware EngineerImprove and measure service performance
This question evaluates performance engineering and observability skills—specifically SLIs/SLOs definition, instrumentation and profiling, load-testing, bottleneck identification, and optimization trade-offs for stateless HTTP microservices.
System DesignTechnical Screen - TikTokMediumSoftware EngineerIntroduce yourself and explain your project
This question evaluates communication, ownership, leadership, and impact articulation by prompting a personal introduction and a focused project narrative covering business context, responsibilities, delivered features, and key challenges.
Behavioral & LeadershipTechnical Screen
TikTok