Katkat

Company

TikTok interview questions

176 practice questions in the style of TikTok's interviews, covering Statistics & Math, Coding & Algorithms, Analytics & Experimentation, Machine Learning, Behavioral & Leadership, Software Engineering Fundamentals, Product / Decision Making, Data Manipulation (SQL/Python), System Design, ML System Design, Product Design & Strategy.

Questions176

18 easy118 medium40 hard

Your progress0/176

TikTok interview questions by the numbers

Last updated

Katkat has 176 TikTok interview questions. The largest topics are Coding & Algorithms (33%), Behavioral & Leadership (14%) and Data Manipulation (SQL/Python) (13%). By difficulty: 10% easy, 67% medium and 23% hard. The most common round is Technical Screen (72%). Frequent concepts include Algorithms, Strings, Arrays and Two Pointers.

Difficulty

  • Easy10% · 18
  • Medium67% · 118
  • Hard23% · 40

Interview rounds

  • Technical Screen72% · 126
  • Onsite18% · 32
  • Online Assessment5% · 9
  • HR Screen5% · 8
  • Other1% · 1

Roles

  • Software Engineer41% · 72
  • Data Scientist38% · 67
  • Machine Learning Engineer13% · 22
  • Data Engineer3% · 6
  • Product Manager3% · 6

Frequent concepts

  • Algorithms5% · 8
  • Strings4% · 7
  • Arrays2% · 4
  • Two Pointers2% · 4
  • Causal Inference2% · 3
  • Data Structures2% · 3

Showing 61–90 of 176 results

  • Design overload protection with load shedding 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.

    TikTokSoftware EngineerSystem DesignTechnical Screen
  • Design query generation to maximize CTR evaluates ML product requirements, data/labeling, modeling, serving architecture, evaluation, monitoring, and trade-offs in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    TikTokMachine Learning EngineerML System DesignTechnical Screen
  • This question evaluates a data scientist's competency in designing multi-objective recommender systems that balance user growth and creator monetization, covering ranking objective formulation, per-impression value estimation, constraint enforcement (latency, diversity, fairness/exposure), offline-to-online metric validation, cold-start and exploration strategies, and interference/attribution challenges within the Machine Learning domain. It is commonly asked to assess the ability to reason about trade-offs between business and user metrics, to define measurable objectives and validation plans, and to demonstrate both conceptual understanding and practical application of system design and evaluation.

    TikTokData ScientistMachine LearningHR Screen
  • This question evaluates expertise in experimental design, causal inference, statistical power and minimum detectable effect calculation, variance-reduction techniques, sequential monitoring, and diagnostics for interference, spillovers, and weekly seasonality in A/B testing.

    TikTokData ScientistAnalytics & ExperimentationTechnical Screen
  • This question evaluates a candidate's ability to design scalable ML-driven systems for detecting and classifying privacy-sensitive and PII-containing records across structured and unstructured data, testing competencies in data engineering, machine learning (including deep learning and LLM/RAG integrations), system architecture, and privacy/security considerations. It is commonly asked to probe reasoning about functional and non-functional requirements, trade-offs in detection and classification approaches, evaluation metrics like precision and recall, feedback loops and operational scaling, and it falls under ML system design with a practical, application-level focus rather than purely conceptual abstraction.

    TikTokSoftware EngineerML System DesignTechnical Screen
  • This question evaluates analytics data modeling and event-driven warehousing skills, including schema design, metric derivation, partitioning/clustering strategies, and data-quality concerns such as deduplication, late arrivals, and idempotency.

    TikTokSoftware EngineerSystem DesignTechnical Screen
  • This question evaluates expertise in ML system design for multimodal large models, covering deployment under compute and GPU memory constraints as well as large-scale retrieval and processing of video captions and embeddings.

    TikTokMachine Learning EngineerML System DesignTechnical Screen
  • Practice designing an anti-cheat product strategy for competitive online games with real-time matches, ranked leaderboards, and an in-game economy. The solution covers detection signals, streaming and batch pipelines, modeling approaches, prevention, graduated enforcement, appeals, false-positive recovery, and trust metrics.

    TikTokProduct ManagerProduct Design & StrategyOnsite
  • This question evaluates dynamic programming, state-space reachability, and constrained transition reasoning, along with skills in hash-based memoization and time/space complexity analysis.

    TikTokMachine Learning EngineerCoding & AlgorithmsOnsite
  • This question evaluates a candidate's understanding of dynamic programming and string-processing skills, along with algorithmic complexity analysis for segmentation problems.

    TikTokMachine Learning EngineerCoding & AlgorithmsTechnical Screen
  • Evaluates diagnosis of brand-name search relevance and safety issues using analytics and experimentation. Strong answers define relevance, satisfaction, and harmful-content metrics, find root causes, and validate fixes offline and online.

    TikTokData ScientistAnalytics & ExperimentationOnsite
  • This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Diagnose Traffic Allocation in A/B Test Results states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    TikTokData ScientistAnalytics & ExperimentationTechnical Screen
  • This question evaluates a Data Scientist's competency in operational analytics, metric integrity, root-cause analysis, and experiment interpretation, covering concepts such as logging latency, sample ratio assessment, and product instrumentation awareness.

    TikTokData ScientistAnalytics & ExperimentationOnsite
  • This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Differentiate virtual and pure virtual functions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    TikTokMachine Learning EngineerCoding & AlgorithmsTechnical Screen
  • Practice allocating budget between two TikTok mobile-game ad creatives using funnel and ROI analysis. The solution covers CTR, CVR, IPM, CPI, ARPU, ROAS, marginal return, creative fatigue, growth headroom, long-term LTV, confidence, and exploration-versus-exploitation decisions.

    TikTokProduct ManagerProduct / Decision MakingOnsite
  • This question evaluates understanding of Python mutability and copying semantics — including how mutable versus immutable objects affect function arguments and container behavior — and knowledge of the Global Interpreter Lock (GIL) and concurrency models.

    TikTokSoftware EngineerData Manipulation (SQL/Python)Technical Screen
  • This question evaluates a candidate's competency in causal machine learning, heterogeneous treatment effect estimation, off-policy evaluation, and fairness-aware policy design using observational data.

    TikTokData ScientistMachine LearningTechnical Screen
  • This question assesses the candidate's deep understanding of C++ memory management, the runtime implementation of polymorphism, and the performance characteristics of standard containers.

    TikTokSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
  • This question evaluates understanding of Direct Preference Optimization (DPO) for fine-tuning large language models, assessing conceptual differences from PPO-based RLHF and the competency to design pairwise preference training datasets.

    TikTokSoftware EngineerMachine LearningTechnical Screen
  • This problem tests your understanding of core transformer efficiency techniques, specifically focusing on how they improve memory footprint, latency, and sequence length handling.

    TikTokMachine Learning EngineerMachine LearningTechnical Screen
  • This question evaluates a candidate's understanding of Java concurrency primitives and concurrent collection implementations, focusing on thread-safety, synchronization mechanisms, lock-free techniques, and blocking versus non-blocking queue behavior.

    TikTokSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
  • This question evaluates understanding of Java framework internals and related competencies including dependency injection, aspect-oriented programming and proxy mechanisms, transaction management, annotation processing, bean lifecycle, classpath scanning, bean scopes, and circular dependency detection or resolution.

    TikTokSoftware EngineerCoding & AlgorithmsTechnical Screen
  • This question evaluates a candidate's competency in SRE architecture and reliability engineering, covering Kubernetes fundamentals, pod failure troubleshooting, SLO/SLA/SLI reasoning, multi-layer latency diagnosis, and SQL versus NoSQL trade-offs within the System Design domain.

    TikTokSoftware EngineerSystem DesignTechnical Screen
  • Tests understanding of the TLS handshake, asymmetric vs. symmetric cryptography in HTTPS, certificate authority verification, and the mechanics of forward secrecy versus intercepting HTTPS proxies.

    TikTokSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
  • This question evaluates understanding of modern NLP model architecture and evaluation metrics, specifically Transformer block components, key distinctions between GPT and BERT including pretraining objectives and usage, and precision/recall interpretation, testing competencies in deep learning architecture knowledge, model selection reasoning, and metric-based evaluation within the Software Engineering Fundamentals domain for a Machine Learning Engineer role. It is commonly asked because it probes both conceptual understanding of architectures and pretraining paradigms and practical application of performance trade-offs—assessing conceptual understanding alongside practical application in threshold-based precision versus recall decisions.

    TikTokMachine Learning EngineerSoftware Engineering FundamentalsTechnical Screen
  • This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Explain Your Experience and Interest in Tech Role states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    TikTokData ScientistBehavioral & LeadershipHR Screen
  • This question evaluates behavioral and leadership competencies within data engineering, focusing on impact measurement, decision-making under ambiguity, incident response and mitigation, stakeholder management, prioritization under schedule changes, and mission alignment for public-sector contexts.

    TikTokData EngineerBehavioral & LeadershipTechnical Screen
  • Explain Your System Architecture 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.

    TikTokSoftware EngineerSystem DesignOnsite
  • Practice explaining a difficult engineering project through ownership, technology choices, scaling constraints, and measured trade-offs. The model answer uses a clearly hypothetical ingestion service to show how to discuss alternatives, bottlenecks, rollout evidence, and lessons without exposing private project details.

    TikTokBackend Software EngineerBehavioral & LeadershipOnsite
  • This question evaluates proficiency in SQL result-set interpretation and reasoning about joins, filters, aggregations, window functions, NULL handling, duplicate rows, and ordering within the Data Manipulation (SQL/Python) domain for a Data Engineer role.

    TikTokData EngineerData Manipulation (SQL/Python)Technical Screen

TikTok interview experiences

All 27 →
  • AI Agent Second Round in MandarinTikTok · Software Engineer · Intern · Technical Screen · Sep 2026

    TikTok SWE AI Agent Intern, second-round interview report. This was the second round, and the entire conversation was in Mandarin. I started with a self-introduction, followed by a deep dive into my research project. Fundamentals / business design How HTTPS works. Explain the TLS/SSL handshake process and CA certificate validation in detail. Follow-up: During data transmission, is symmetric or as…

  • Three Weekly USDS Rounds Ending in RejectionTikTok · Software Engineer · Onsite · Aug 2026
    Rejected

    The rounds were basically scheduled one per week. 1st round, coding: Use round-robin scheduling to process tasks. Each task has a task_id, seller_id, tier (VIP or STANDARD), and priority (1 is high and 3 is low). Within one seller's backlog, tasks with smaller priority numbers must be processed first. Tasks with the same priority follow their arrival order, using FIFO. Across sellers, use weighte…

  • Two Completed Problems and Unexpected IDE TimeoutsTikTok · Software Engineer · Senior+ · Technical Screen · Aug 2026
    Rejected

    Someone contacted me through a professional network, so I treated the interview as practice and a chance to see the market. The two questions were LeetCode 159 and 93. I stumbled a little on the problems, but I did write both solutions. Their Python coding IDE was very bad. It timed out several times, which made me think I had written an infinite loop, but the environment was actually just runnin…

  • Software Engineer interview at TikTokTikTok · Software Engineer · Jul 2026

    The recruiter gave me a broad sense of the role and scheduled the interviews, but I could not get much detail about the topics or how many stages remained. HR replied quickly, yet the process structure stayed unclear. The first technical stage was a LeetCode question. A later combined stage included technical discussion plus another LeetCode problem. Once interviewing started, things moved along,…

  • After applying, I started with a recruiter conversation centered on my resume. The recruiter walked through it with me, and the interview team made it clear that I needed to know my own CV inside out. Later interviews went deeper into the projects I had listed. I got detailed follow-up questions about specific decisions, my reasoning, and what happened as a result. My sense was that the exact for…

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