Data Scientist Interview Questions

Showing 631–641 of 641 results

• WaymoEasy·Data Scientist
  Model wins-until-failure and expected future wins

  This question tests your ability to model geometric distributions and apply maximum likelihood estimation (MLE) to censored data.

  Statistics & MathOnsiteStatisticsMLEProbability
• WaymoMedium·Data Scientist
  SQL: Average Ride Rating in Users' First and Third Active Months by City

  Write a PostgreSQL query that compares average ride ratings in each user's first and third active months, grouped by city and averaged over individual rides. Tests ranking distinct active months per user, window functions, NULL ratings and weighting.

  Data Manipulation (SQL/Python)Onsite
• WaymoMedium·Data Scientist
  SQL: Users With No Rides in the Most Recent 7-Day Window, Including Non-Riders

  Write a PostgreSQL query that lists users with no rides in the most recent 7-day window, including users who never rode. Tests anchoring a date window to the data, inclusive boundaries, and anti-join logic that keeps users without matching rides.

  Data Manipulation (SQL/Python)Onsite
• WaymoMedium·Data Scientist
  Welch's t-Test p-Value for a Routing Experiment on Time to Pickup, and Its Validity

  Filter rides to one city and month, join users to their experiment variants, and compute a Welch's t-test p-value on time to pickup in Python. Then judge whether the routing test supports a conclusion and design a better experiment for a shared fleet.

  Analytics & ExperimentationOnsite
• YYelpHard·Data Scientist
  Design a Cold-Start-Aware Recommender

  This question evaluates a data scientist's expertise in production recommender systems, covering cold-start strategies, two-stage retrieval and ranking model design, multimodal feature engineering, exploration–exploitation, bias-corrected experimentation, and low-latency serving.

  Machine LearningOnsite
• YYelpHard·Data Scientist
  Handle PM Ambiguity and Drive Outcomes

  This question evaluates leadership, stakeholder management, and incident response competencies within a data science context, including the ability to define measurable success metrics, negotiate scope under ambiguity, and make data-driven decisions during product regressions.

  Behavioral & LeadershipOnsite
• ZAZest AIHard·Data Scientist
  Build a fair loan classifier

  This question evaluates competency in supervised classification and credit risk modeling, covering data exploration and preparation, model selection, evaluation metrics, threshold setting, fairness and regulatory considerations, interpretability, validation, and monitoring.

  Machine LearningOnsite
• ZAZest AIHard·Data Scientist
  Compute tree depth and meeting rooms

  This question evaluates skills in tree traversal and recursion for computing maximum depth of a binary tree, alongside interval scheduling and resource allocation for determining the minimum number of meeting rooms, testing reasoning about data structures such as trees and interval endpoints.

  Coding & AlgorithmsOnsite
• ZAZest AIHard·Data Scientist
  Diagnose overfitting from error curves

  This question evaluates the ability to recognize and diagnose model generalization problems—specifically overfitting—by interpreting training, validation, and test error curves and understanding validation procedures and sources of variance.

  Machine LearningOnsite
• ZooxEasy·Data Scientist
  Choose fastest way to transfer 2 TB

  This question evaluates a candidate's ability to compare large-scale data transfer methods and reason about trade-offs among bandwidth, latency, security, cost, and logistics, reflecting competency in data engineering, networking, and systems design.

  Coding & AlgorithmsOnsite
• ZooxEasy·Data Scientist
  Solve estimation and probability brainteasers

  This question evaluates quantitative estimation, unit conversion, geometric scaling, and basic probability skills across multiple short brainteaser prompts.

  Statistics & MathOnsite