Snapchat Data Scientist Interview Questions
Snapchat Data Scientist interview questions focus on product-driven analytics at scale: expect SQL and Python fluency, rigorous A/B testing and experiment-design questions, plus applied machine learning or modeling scenarios framed around user engagement, ad performance, and real-time social features. What’s distinctive is the product emphasis — interviewers assess your ability to translate messy event data into clear product metrics, reason about causal inference and rollout risk, and propose actionable experiments that move engagement or revenue. Technical depth is balanced with communication and trade‑off judgement. For interview preparation, practice medium-to-hard SQL problems, refresh statistical inference and experiment diagnostics, and rehearse end-to-end product case studies where you define metrics, identify biases, and recommend interventions. Prepare concise walk-throughs of past projects that highlight business impact and code or analysis samples. Timebox mock screens to polish clear, data‑driven storytelling and be ready to discuss scaling, latency, and data-quality tradeoffs when modeling user behavior.
Compute posterior spam risk from flags
A binary classifier flags spammy requesters. Last week the base rate of spam among all requesters was 12%. The classifier has true positive rate (TPR)...
Design an experiment for spam filtering impact
Experiment Design: Stricter Spam Filter Impact on Friend Requests Context You run a social app with a friend-request system. A stricter spam filter wi...
Influence a senior partner with data
Describe a time you had to influence a senior cross-functional leader to change a launch plan based on ambiguous A/B test results. Be specific: the de...
Compute CTR and metrics with pandas
Using pandas only, compute banner and story metrics. Assume today is 2025-09-01 and 'last 7 days' means 2025-08-26 to 2025-09-01 inclusive. You are gi...
Decide whether to launch Group Story
A new Group Story feature may cannibalize regular stories but increase overall engagement. Propose the experiment and decision framework: 1) Identify ...
Design and analyze a banner A/B test
A/B Test Design: Home-Page Banner You are deciding whether to add a home-page banner in a consumer app. Design and analyze the A/B test end-to-end. As...
Explain Random Forest randomness and implications
Random Forest — Rigor and Practical Choices Context: You are building a binary classifier with a Random Forest. The dataset has 100,000 rows, 100 feat...
Derive logistic regression and thresholds
Logistic Regression Deep Dive (Binary Classification) Assume a binary classification setting with observations {(x_i, y_i)} for i=1..n, where x_i ∈ R^...
Optimize Churn Prediction: Feature Engineering and Model Selection
Weekly Churn Prediction (10M users): Feature Engineering, Model Choice, Explainability, and Debugging Scenario You own a weekly churn-prediction pipel...
Influence Partner Teams Without Formal Authority: Strategies Explained
Behavioral & Leadership: Cross-Functional Influence, Feedback, and Prioritization Context You are interviewing for a Data Scientist role. Imagine a cr...
Compute expectations and test fairness for coin flips
You are analyzing repeated flips of a (possibly unfair) coin. Setup Let the probability of Heads be \(p\) (unknown in general). Assume flips are indep...
Calculate Posterior Probability Using Bayes' Theorem Example
Bayes' Theorem Toy Problem: Spam-Flag Example Context You are evaluating a simple classifier that flags messages as spam. Based on historical data, yo...
Design A/B Test for New Recommendation Algorithm Launch
A/B Test Design: New Recommendation Algorithm Objective Design a rigorous A/B test to estimate the incremental impact of a new recommendation algorith...
Monitor Friend-Request System for Quality and Abuse
Friendship +--------------+-------------+---------------------+---------------------+ | requester_id | approver_id | request_ts | approval_ts...
Compute same-day acceptance metrics last week
Assume today is 2025-09-01; interpret 'last week' as 2025-08-25 through 2025-08-31 inclusive, using UTC dates. You have the following schema and sampl...
Compute User Retention and Analyze Event Data
user_events +---------+---------------------+------------+-------+ | user_id | event_time | event_type | page | +---------+-----------------...
How to Update Bayesian Model for Concept Drift?
Beta–Binomial CTR Model: Prior, Likelihood, Posterior, Smoothing, Intervals, and Drift Context You are discussing statistical foundations for a Bayesi...
Compute User Group Stories and Aggregate Story Engagement
user_story_engagement +---------+----------+------------+------------+-------+-------+ | user_id | story_id | story_type | created_at | views | likes ...
Determine Optimal Energy Project for 10% ROI Target
Investment Selection and ROI Sizing for a New Renewable Project Scenario An energy company is evaluating investments in new renewable projects and mus...
Design A/B Tests for Banner Ad and Group-Story Feature
Product Decision Cases: Banner Ad and Group-Story Feature Context You are evaluating two product decisions in a consumer social app: - Adding a new ba...