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 a short-video recommendation system
Design a recommendation system for a short-video feed product. Your answer should cover the full pipeline: 1. Objective and labels: Define what the sy...
Explain core ML concepts and diagnostics
You are in an ML breadth interview for a Senior Applied Scientist role. Answer the following conceptual questions clearly and practically (definitions...
Implement Linear Regression Gradient Descent
Implement simple linear regression from scratch using batch gradient descent. Given training data with one input feature x and target y, fit a model o...
Handle cold start, dropout, and training stability
Machine Learning deep dive Answer the following conceptual questions (you may use equations and small examples). A) Recommender systems: cold start 1....
Forecast bikes available at a station
Data Analysis / Forecasting Prompt You are given historical Citi Bike (bike-share) trip and station status data. Each station has a fixed dock capacit...
Compare preference alignment methods for LLMs
Question You’re asked to discuss preference alignment approaches for large language models. Task Compare several alignment methods and explain when yo...
What are linear regression assumptions?
You fit an ordinary least squares (OLS) linear regression model. 1) What are the key assumptions behind OLS (for unbiasedness and for valid inference)...
Explain core components of reinforcement learning
In reinforcement learning, we model an agent that interacts with an environment over time. The agent observes the state of the environment, takes acti...
Design a ride-hailing ETA system
During a first-round Data Scientist interview, you are asked a product and machine learning case question: Design an estimated time of arrival (ETA) p...
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 the bias–variance trade-off
Explain the bias–variance trade-off in supervised learning. In your answer, cover: - What bias and variance mean in the context of a prediction model....
Improve Model Generalization with Cross-Validation and Feature Engineering
Predict Next-Month Orders: Train/Test Split, Pipeline, and AUC Context You are given a cleaned tabular retail dataset as a pandas DataFrame df. The bi...
Design a Machine Learning Recommendation System Pipeline
System Design: End-to-End ML Recommendation System Scenario You are building an end-to-end machine-learning-powered recommendation system for a large ...
Explain core ML and DL fundamentals
Question Answer the following machine-learning / deep-learning concept questions. Where useful, include the formula, the intuition, and a small worked...
Explain Layer Normalization in Transformers
Layer Normalization in Transformers: Placement, Gradients, and Practical Trade-offs Task Explain Layer Normalization (LayerNorm) as used in Transforme...
Build and evaluate click prediction models
Click-Through Rate (CTR) Prediction: Build, Compare, and Justify Models Context You are given a tabular dataset for binary click prediction (click = 1...
How would you build UberEats ranking?
UberEats wants to improve its recommendation or ranking system for restaurants shown to users on the home feed or in search results. Design the machin...
Test whether samples follow a binomial distribution
You collect a dataset that you believe comes from a binomial process. Each observation is a count of successes. - You have i.i.d. samples \(x_1,\dots,...
Design navigation-safety simulation parameters and experiments
You must design a simulation-based evaluation for navigation safety of an autonomous agent. Be specific: a) Enumerate scene parameters to vary and jus...
Deploy multi-armed bandits safely
Online bandit with 3 variants, churn guardrail, and delayed conversions Context You are running an online experiment with 3 variants (including contro...