Data Scientist Machine Learning Interview Questions
Practice 402 real Machine Learning interview questions for Data Scientist roles. From companies including Meta, Amazon, Google, Capital One, TikTok.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Design a Real-vs-Fake DNA Classifier
You are given DNA sequences over the alphabet {A, C, G, T}. A small labeled dataset contains both real and fake DNA sequences. In addition, you have a...
Explain Overfitting and Transformer Basics
Answer the following machine learning questions in a self-contained way: 1. What is overfitting? How would you recognize it from training and validati...
Engineer and Impute ZIP Features
You are building a predictive model for a product team. For some users, you have address fields such as street, city, state, and ZIP code. 1. What fea...
Determine When a Quadratic Has Finite Minimum
Consider the unconstrained real-valued optimization problem \[ \min_{x \in \mathbb{R}^n} f(x) = x^\top Qx + c^\top x, \] where \(Q \in \mathbb{R}^{n \...
How would you design an ETA prediction system?
Design an end-to-end ETA (Estimated Time of Arrival) system for a maps / ride-hailing / delivery product. Assume users request an ETA for a trip from ...
Diagnose overfitting from error curves
You are evaluating a supervised machine learning model. You are shown a plot where the x-axis is training epoch or model complexity and the y-axis is ...
Build a DNA authenticity classifier
You are given DNA sequences composed of the characters A, C, G, and T. The task is to predict whether a sequence is real biological DNA or a fake / sy...
Explain Feature, Model, and Validation Choices
You are interviewing for a Data Scientist role. Describe how you would approach an end-to-end machine learning project on large-scale data. In your an...
Model Soccer Shot Conversion
You are given event-level soccer shot data, and possibly tracking or contextual data. Build a model that predicts the probability that a shot becomes ...
Run EDA and train models while preventing overfitting
You are given a tabular regression dataset \(\{(x^{(j)}, y^{(j)})\}_{j=1}^M\) with numeric and categorical features and a continuous target. Describe ...
Design a Homepage Store Recommender
You are designing the homepage store recommendation system for a food-delivery app similar to DoorDash. When a user opens the app, the online request ...
Design and evaluate a RAG system
You are interviewing for an L5 Data Scientist role focused on LLM applications. Design a retrieval-augmented generation (RAG) system for an internal q...
How to validate production models?
You are interviewing for a fintech model-validation team that acts as a second line of defense for credit-risk and fraud models. A hiring manager asks...
Predict bike demand and avoid overfitting
You are given historical data for a city bike-sharing system. Available fields include station_id, hourly timestamp, number of bike pickups and return...
Explain SHAP and build an ML project
Part A: SHAP 1. What is SHAP (SHapley Additive exPlanations) trying to measure? 2. How do you interpret: - A local SHAP explanation for a single pr...
Predict Bike Dock Demand
You are working on a docked bike-sharing system. Build a model that predicts how many bikes will be checked out from a specific dock in the next hour....
Explain L1 vs L2 and ridge vs lasso
Explain the differences between: 1. L1 vs L2 regularization (how they change the objective, geometry/intuitions, and typical effects on learned parame...
Explain KNN and how to tune it
K-Nearest Neighbors (KNN) fundamentals You are interviewing for a Data Scientist role. 1. Explain how the KNN algorithm works for both classification ...
Model Driver Acceptance Probability
Design a machine learning system to predict the probability that a driver accepts a trip or delivery offer. Your answer should cover: - the prediction...
How detect duplicate card records?
You are given a dataset of credit card transaction records and suspect that some records are duplicates. Discuss: - What real-world situations could c...