Interview Questions

Showing 8341–8370 of 9403 results

• TikTokMedium·Data Scientist
  Analyze promo anomaly and design risk guardrails

  This question evaluates a candidate's ability to diagnose promotional anomalies, distinguish coordinated abuse from organic virality, design real-time approve/hold/reject decisioning with cost trade-offs, and specify experiment and monitoring plans, testing competencies in fraud analytics, operational risk modeling, and experimentation.

  Analytics & ExperimentationHR Screen
• TikTokHard·Machine Learning Engineer
  Answer ML fundamentals and diagnostics questions

  This problem tests your theoretical understanding of model diagnostics, ensemble learning mechanics, and the trade-offs between optimization strategies in machine learning.

  Machine LearningOnline AssessmentEnsemble MethodsRegularizationMetrics
• TikTokMedium·Software Engineer
  Answer 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
• TikTokMedium·Software Engineer
  Answer 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
• TikTokMedium·Data Scientist
  Balance Customer Satisfaction with Fraud Prevention: Key Metrics to Track

  Evaluates risk-decisioning trade-offs between customer experience and fraud prevention in payment products. Strong answers cover cost-sensitive thresholds, false declines, fraud loss, experimentation, monitoring, and delayed labels.

  Analytics & ExperimentationOnsite
• TikTokMedium·Product Manager
  Break a Palindrome Algorithm

  Practice the greedy algorithm for breaking a palindrome into the lexicographically smallest non-palindrome by one character replacement. The solution explains scanning the left half, skipping the middle character, changing the first non-a to a, handling all-a cases, proving correctness, and analyzing complexity.

  Product / Decision MakingOnline Assessment
• TikTokMedium·Data Scientist
  Calculate Conversion Rate from Ad Clicks to Page Visits

  This question evaluates a candidate's competency in event-level data manipulation and metric computation using SQL or Python, including time-based aggregation, deduplication, and joining or windowing of event streams.

  Data Manipulation (SQL/Python)Technical Screen
• TikTokMedium·Data Scientist
  Calculate Day-7 Retention Rate from User Post Data

  This question evaluates a candidate's competency in SQL and Python data wrangling, emphasizing date arithmetic, window functions, grouping, and conditional aggregation for cohort and retention calculations.

  Data Manipulation (SQL/Python)Technical Screen
• TikTokEasy·Data Scientist
  Calculate Expected Draws for X > 0.8 in Uniform(0,1)

  This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Calculate Expected Draws for X > 0.8 in Uniform(0,1) states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Statistics & MathTechnical Screen
• TikTokMedium·Data Scientist
  Calculate User Registration Date and 7-Day Retention Rate

  This question evaluates the ability to perform time-based data manipulation and cohort retention analysis using SQL/Python, including deriving registration dates, aggregating posts within time windows, and computing retention metrics.

  Data Manipulation (SQL/Python)Technical Screen
• TikTokMedium·Data Scientist
  Calculate valid daily usage with gap constraints

  This question evaluates a candidate's ability to manipulate temporal intervals, including clipping to a specified day window, merging touching or overlapping segments, detecting gaps, and aggregating minute-level durations using SQL window functions and date/time arithmetic, and belongs to the Data Manipulation (SQL/Python) domain.

  Data Manipulation (SQL/Python)Technical Screen
• TikTokMedium·Data Scientist
  Compare Random Forests and Boosted Trees: Bias, Variance, Speed

  Evaluates practical trade-offs between Random Forests and gradient-boosted trees for tabular ML. Strong answers compare bias, variance, speed, interpretability, overfitting, production fit, and feature scaling needs.

  Machine LearningTechnical Screen
• TikTokMedium·Data Scientist
  Compute 7-day rolling complaint/order ratio in SQL

  This question evaluates SQL data manipulation skills, specifically time-based aggregations, sliding window functions, joins to include entities with no events, and numeric casting within the Data Manipulation (SQL/Python) domain.

  Data Manipulation (SQL/Python)Technical Screen
• TikTokMedium·Data Scientist
  Compute Averages of Unique Numbers in Dictionary Lists

  This question evaluates data manipulation and aggregation skills, focusing on handling duplicate values within collections and computing numerical summaries of list data.

  Coding & AlgorithmsOnsite
• TikTokMedium·Data Scientist
  Compute CTR drop with exclusions

  This question evaluates a candidate's ability to compute time-windowed click-through rates using SQL aggregations, joins, filters and data-cleaning (excluding suspicious ads) while handling edge cases such as missing days, minimum-impression thresholds, division-by-zero, and integer-division pitfalls.

  Data Manipulation (SQL/Python)Onsite
• TikTokMedium·Data Scientist
  Compute and rank top bad advertisers

  This question evaluates proficiency in SQL data manipulation and analytics, including time-window filtering, JOINs, aggregation and deduplication, rate calculations, and window-function–based ranking.

  Data Manipulation (SQL/Python)Technical Screen
• TikTokMedium·Machine Learning Engineer
  Compute city skyline silhouette

  Compute city skyline silhouette 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
• TikTokMedium·Data Scientist
  Compute cluster-aware significance and sequential corrections

  This question evaluates competency in clustered randomized experiment analysis, including calculation of design effect and effective sample size, cluster-robust inference for differences in proportions, sequential alpha spending (O’Brien–Fleming-style) and comparisons with Bonferroni, Holm–Bonferroni adjustments for multiple guardrail metrics, and Bayesian ROPE interpretation. It is in the Statistics & Math domain and is commonly asked to probe how candidates handle intra-cluster correlation, control Type I error across interim looks and multiple metrics, and demonstrate both conceptual understanding and practical application of power, duration, and multiplicity trade-offs.

  Statistics & MathHR Screen
• TikTokMedium·Data Scientist
  Compute last-to-previous ad impression gaps

  This question evaluates proficiency in data manipulation and time-based analytics, covering SQL window functions, timestamp arithmetic, and grouping/ordering semantics within the Data Manipulation (SQL/Python) domain.

  Data Manipulation (SQL/Python)Technical Screen
• TikTokMedium·Software Engineer
  Compute 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
• TikTokMedium·Machine Learning Engineer
  Compute minimum path sum in a triangle

  This problem tests your ability to optimize path calculations in a non-linear data structure using dynamic programming, specifically focusing on space complexity optimization.

  Coding & AlgorithmsTechnical ScreenDynamic ProgrammingArraysSpace Optimization
• TikTokMedium·Software Engineer
  Compute 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
• TikTokHard·Data Scientist
  Control confounding in observational ad lift

  This question evaluates mastery of observational causal inference for ATE estimation, covering causal DAGs and identification, pre-treatment adjustment, propensity-score and inverse-probability/doubly-robust estimation, diagnostic checks, sensitivity analysis for unobserved confounding, and variance/uncertainty quantification in the context of ad exposure data. It is commonly asked because real-world advertising analyses cannot rely on randomization and interviewers need assurance of both conceptual understanding of identification assumptions and practical application of estimation and diagnostic techniques; the category is Statistics & Math and the level of abstraction spans conceptual reasoning and applied implementation.

  Statistics & MathOnsite
• TikTokMedium·Data Scientist
  Count buggy vs non-buggy by employer

  This question evaluates proficiency in SQL data manipulation—particularly conditional aggregation and join semantics—for counting categorized records across related tables in a data science context.

  Data Manipulation (SQL/Python)Online Assessment
• TikTokMedium·Software Engineer
  Count 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
• TikTokMedium·Software Engineer
  Count 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
• TikTokMedium·Software Engineer
  Count 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
• TikTokMedium·Machine Learning Engineer
  Count subarrays summing to target

  This problem tests your ability to optimize subarray sum calculations from an O(n^2) approach to O(n) using a hash map for prefix sum tracking.

  Coding & AlgorithmsTechnical ScreenArraysHash MapPrefix Sum
• TikTokMedium·Data Engineer
  Debug a Hive Query for DAU

  This question evaluates proficiency in Hive/SQL query formulation, data partitioning and pruning, join and aggregation semantics, timestamp handling, and performance tuning for large-scale analytics.

  Data Manipulation (SQL/Python)Technical Screen
• TikTokMedium·Data Engineer
  Debug a Hive insert query

  This question evaluates a candidate's ability to debug Hive INSERT/SELECT operations, focusing on schema and column alignment, data types and casts, partition handling, file formats/SerDe, ACID/transactional constraints, and syntax or reserved keyword issues.

  Data Manipulation (SQL/Python)Technical Screen