Voleon Group Interview Questions
Master your tech interview with our curated database of real questions from top companies.
Compute robust inference under skew and outliers
A/B test with skew, outliers, heteroskedasticity, missingness, and multiplicity You are comparing two independent product variants that produce a cont...
Design and diagnose a regression pipeline
CLV_90 Prediction Pipeline under Zero-Inflation, Heavy Tails, and Multicollinearity Context You need to predict 90-day customer value (CLV_90) at the ...
Analyze time-zoned events with pandas
You are given two pandas DataFrames. events columns: user_id:int, ts:str ISO-8601 with timezone (e.g., '2025-08-31T23:58:43-07:00'), event:str in {'si...
Diagnose and interpret regression assumptions
OLS for Signups with Diagnostics and Alternatives You are given a cleaned dataset with the following columns: - signups: non-negative integer count ta...
Build a regularized regression pipeline
Technical Screen: End‑to‑End Signup Prediction with scikit‑learn Context You are given a cleaned tabular dataset with marketing and product metrics. Y...
Load and visualize large CSV robustly
You're screen-sharing in a HackerRank environment with Python 3, pandas, numpy, seaborn, and matplotlib available. You are given a single file data.cs...
Design circular sliding-window ratio tracker
You are given a circular binary array A of length n (A[i] ∈ {0,1}) and a fixed window size w (1 ≤ w ≤ n). Define r (i) as the fraction of 1s within th...
Discuss Résumé Highlights and Past Work Experience.
Behavioral HR Screen — Data Scientist (45 minutes) Setup A 45-minute conversation with a current employee focusing on your résumé, motivations, search...
Pre-process Financial Data for Linear Regression Modeling
market_data +------------+----------+----------+--------+ | date | feature1 | feature2 | target | +------------+----------+----------+--------+ ...
Describe Your Machine Learning Project Experience
Machine Learning Experience: Walk Through a Project Context You are interviewing for a Data Scientist role. In an HR screen, you’re asked to concisely...
Explain P-Value Reporting and Bootstrap for Coefficient Estimation
Scenario Technical screen — statistical inference checks after regression. Questions 1) You observe a regression output where a coefficient's p-value ...
Fit Linear Regression: Analyze Economic Impact of Coefficients
Scenario You are given a tabular financial dataset df where the column target is the dependent variable (e.g., next-period return or excess return), a...