Snapchat Interview Questions
Practice the exact questions companies are asking right now.
Count ways to decode digit string
You are given a string s consisting of digits '0' to '9'. The string encodes a message using the following mapping: - '1' → A, '2' → B, ..., '26' → Z....
Compute longest increasing path in matrix
You are given an m x n grid (matrix) of integers grid, where m >= 1 and n >= 1. A path in the matrix is a sequence of cells where: - You may move from...
Design a harmful content detection system
System Design: End-to-End Harmful Content Detection (Multilingual, Multimodal) Context You are designing a safety system for a large, mobile-first, ep...
Implement sin(x) with precision constraints
Coding Question: Implement sin(x) Implement a function that returns an approximation of the trigonometric sine function. Function signature - Input: a...
How do you decide with limited information?
Behavioral Question Describe a time you had to make an important decision with incomplete, ambiguous, or conflicting information. Include: - What deci...
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...
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...
Handle cards, islands, Trie, median
Question LeetCode 914. X of a Kind in a Deck of Cards LeetCode 694. Number of Distinct Islands LeetCode 208. Implement Trie (Prefix Tree) LeetCode 295...
Explain median vs mean for L1/L2
Median vs Mean Under L1 and L2, and the 2D Extension Task Explain, with intuition and a brief derivation, why: - In 1D, the median minimizes the sum o...
Compare convolutions and transformers
Compare CNNs and Transformers Task Explain the key differences between convolutional neural networks (CNNs) and transformer architectures. Specificall...
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...
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)...
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...
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^...
Solve Open the Lock BFS
Question LeetCode 752. Open the Lock – Given an initial lock state "0000", a target combination, and a list of deadend combinations that cannot be use...
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...