Paypal Interview Questions
Practice the exact questions companies are asking right now.
Design and evaluate a fraud detection strategy
Context You are interviewing for a Fraud Data Scientist role at a payments company. The company has a fraud model and some operational constraints. Pa...
Explain list vs tuple in Python
Question In Python: 1. What are the key differences between a list and a tuple? 2. When would you prefer using a tuple over a list? 3. What are the pe...
Explain and interpret p-values correctly
Context You are evaluating a change to a fraud decision rule (e.g., a new threshold or step-up authentication rule). You run an experiment comparing C...
Write SQL using HAVING and window functions
Context You work on fraud analytics. Assume the following schema (PostgreSQL-like types): transactions - txn_id BIGINT (PK) - merchant_id BIGINT - use...
Explain confounding with an Uber example
Question In the context of analyzing Uber/Uber Eats data, explain what a confounding effect is. 1. Define confounder and why it can bias an observed r...
Solve common search/parse/graph frequency tasks
You are given several independent coding tasks. For each task, write a function that returns the required output. 1) Find insertion index in a sorted ...
Detect credit-card transaction fraud
Credit-Card Fraud Detection: Decisions and System Design Context You are designing a real-time decisioning system for card transactions with strict la...
Design and Analyze A/B Test for Cashback Program
A/B Test Design: Checkout Cashback Program (PayPal) Scenario PayPal plans to launch a checkout cashback program (e.g., "Get 1–5% back when you pay wit...
Boost User Login Rate: Key Metrics to Monitor
Scenario You are the product data scientist responsible for improving a consumer fintech platform's user authentication experience and increasing the ...
Build a real-time ATO model
End-to-end ML Case: Real-time Detection of Venmo Account Takeover (ATO) at Authorization Context Design a real-time machine learning system that score...
Answer career, manager, and team fit questions
Behavioral Questions Answer the following questions in a structured, interview-ready way: 1. Project deep dive: Walk me through a project you worked o...
Design metrics and experiment for donation feature
Product/Experimentation Case Uber Eats is considering a new feature: when a user places an order, they can optionally donate (tip-like or charitable d...
Analyze KPI Drop: Immediate Steps for Stakeholder Persuasion
Behavioral + Mini-Case: Persuading with Data and Responding to a KPI Drop Context You are a Data Scientist interviewing onsite for a role focused on p...
Reduce airport cancellations under causal constraints
You are a Data Scientist on an airport rides team for a ride-hailing marketplace. Airport rides differ from city rides: - Drivers often enter an airpo...
Analyze Success Metrics and Diagnose Crypto Feature Issues
Post-Launch Evaluation: Crypto Trading Feature Context You are a Data Scientist evaluating the post-launch performance of a crypto-trading feature int...
Design an A/B for ATO rule
Experiment Design Case: Real-time ATO Rule for PayPal/Venmo Context: You are designing and analyzing an online experiment to estimate the net business...
Influence Stakeholders Without Authority: Strategies and Examples
Behavioral Interview (Onsite) — Data Scientist at PayPal Prompt You are in a hiring‑manager behavioral conversation. Prepare three concise STAR respon...
Compute top orders and cancellation rate
You work at a ride-hailing company and are analyzing orders (trips) between drivers and riders. Tables drivers - driver_id BIGINT (PK) - home_city TEX...
Should you play a dice payout game?
Two players each roll a fair six-sided die once. - If you win (your roll > opponent’s roll), the opponent pays you $n. - If the opponent wins or it’s ...
Optimize thresholds under fraud costs
Cost-sensitive Thresholding for Fraud (ATO) Classifier Context You are evaluating a binary classifier for account takeover (ATO) fraud on a large vali...