Machine Learning Interview Questions
Practice 639 real Machine Learning interview questions for 2026 — Machine Learning interview questions drawn from Amazon, Meta, Google, TikTok, and Capital One, with real questions from actual interviews and detailed solutions. This collection is built for interview preparation focused on production-ready ML: expect questions that test modeling and mathematics, coding in Python, ML system design, MLOps and deployment, and modern GenAI topics such as transformer fundamentals, embeddings, and retrieval-augmented generation. Companies emphasize reliability, data quality, and end-to-end ownership as much as algorithmic chops. What’s distinctive: interviews now blend theory, coding, and system thinking — you’ll be evaluated on algorithmic intuition, experiment design and metrics, feature and data engineering, model monitoring and drift detection, and cost/reliability tradeoffs for serving models at scale. To prepare, strengthen fundamentals (linear models, trees, probabilistic reasoning), implement end-to-end projects, rehearse ML system-design case studies, and run mock interviews that combine coding, math, and production scenarios.

"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 and validate a cost-sensitive classifier
Binary Purchase Prediction with Delayed Labels and Imbalanced Classes Context - Goal: Ship a real-time binary classifier that predicts whether a user ...
Explain and tune XGBoost; prevent overfitting
XGBoost Tree Booster: Objective, Hyperparameters, Tuning for Imbalanced Detection, and Post-training Use Context: You are building a binary classifier...
Design a News Feed with APIs
Personalized News Feed System Design (Push + Pull) Context You are designing a large-scale personalized news feed for a consumer application. The feed...
Validate and monitor ranking model end-to-end
Expedia Hotel-Ranking Model: Evaluation, Metrics, Diagnostics, Rollout, and KPI Alignment Context: You are building a learning-to-rank (LTR) model to ...
Design a production face recognition system
Design an On-Device Face Recognition System for Mobile Access Control Context You are designing a face-based access control system for mobile devices ...
Achieve 0.95 precision via thresholding
Deploying a High-Precision Classifier on an Imbalanced Dataset You are given a binary classification problem with 50,000 samples and ~5% positives. Th...
Build a leak-free sklearn pipeline
Take-home: Imbalanced Binary Classification Pipeline with scikit-learn You are training a binary classifier on tabular data with the following feature...
Design fraud detection across channels with unknowns
Fraud Detection Strategy for a Multi‑Channel Marketplace Context: You are designing a fraud detection system for a large marketplace operating across ...
Design real-time live-stream recommendations
Design a Real-Time Recommendation System for Live Streams Context: You are designing a recommender for a large live-streaming platform. Assume you hav...
Compare bagging vs boosting on imbalanced data
Fraud Detection on 10M Time-Ordered Transactions (0.5% Fraud) You are building a binary classifier to detect 0.5% fraudulent events among 10,000,000 t...
Derive logistic regression objective and gradients
Context: Binary Logistic Regression You are given a binary classification dataset {(x_i, y_i)}_{i=1}^m with labels y_i ∈ {0, 1}. The model uses the si...
Explain surprisal and its units
You are discussing a language-modeling / NLP project. The interviewer asks about surprisal. 1. Define surprisal for an event/token with probability \(...
Predict User Churn with Effective Modeling Techniques
Predict User Churn with Effective Modeling Techniques Predicting User Churn for a Subscription App Context You are building a model to predict which a...
Identify Unsupervised Techniques for Detecting Fraudulent Transactions
Identify Unsupervised Techniques for Detecting Fraudulent Transactions Unsupervised Fraud Detection: Modeling and Evaluation Without Labels Scenario Y...
Explain XGBoost Parallelism Strategies
Explain How XGBoost Parallelizes Training Scope Describe how XGBoost achieves parallelism: 1. Within a single machine - Histogram-based split findi...
Explain normalization, regularization, CTR, imbalance handling
You are interviewing for an applied ML role. Answer the following fundamentals clearly and concretely (you may use equations and practical examples): ...
Explain unsupervised fraud and evaluation
Explain unsupervised fraud and evaluation Unsupervised Fraud Detection: Methods, When to Use Them, and How to Evaluate Without Reliable Labels Context...
Build an imbalanced classification pipeline with sklearn
Build an imbalanced classification pipeline with sklearn Take-home: End-to-end Imbalanced Binary Classification Pipeline (scikit-learn + imbalanced-le...
Machine Learning Fundamentals: Tree Models, Training, Evaluation, and Embeddings
Machine Learning Fundamentals: Tree Models, Training, Evaluation, and Embeddings This is a concept-check round for an early-career ML engineer. The go...
Rank features using logistic regression coefficients
You are given a binary classification dataset: - X: a 2D array of shape (n_samples, n_features) containing numeric features - y: a 1D binary array of ...