Machine Learning Engineer Interview Questions
Practice 819 real Machine Learning Engineer interview questions for 2026 — real questions from actual interviews with detailed solutions. This collection focuses on the full spectrum companies that hire MLEs today (Meta, Amazon, OpenAI, TikTok, Google) and centers on the concrete problems you’ll face: algorithmic coding, ML-system design, model evaluation and experimentation, and production ML engineering. Machine Learning Engineer interview questions here reflect both research-minded applied roles and engineering-heavy production roles so you can target positions across teams and seniority levels. What makes these interviews distinctive is the blend of software-engineering rigor and ML-specific judgment: expect timed coding rounds (data structures and algorithmic fluency), ML-case and system-design rounds (end-to-end pipelines, scalability, feature stores, monitoring), statistical and evaluation questions, and behavioral storytelling about impact. For interview preparation, focus on four pillars: coding speed and correctness, ML fundamentals (generalization, metrics, bias), system design for ML at scale, and concrete production experience (deployment, observability, cost tradeoffs). Practice mixed-format mock loops that mirror top tech-company rhythms to build the cross-discipline fluency interviewers evaluate.

"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."
Check diagonal and compute window statistics
Question Given a square matrix, determine whether all elements on its main diagonal are identical. LeetCode 346. Moving Average from Data Stream – des...
Count subarrays summing to target
Question LeetCode 560. Subarray Sum Equals K – Given an integer array nums and an integer k, return the total number of continuous subarrays whose sum...
Design query generation to maximize CTR
Question Design an end-to-end query-generation system that maximizes click-through rate (CTR) for a large-scale search/recommendation product. Walk th...
Design a Lens Recommendation System
Design a recommendation system for augmented-reality lenses in a social camera application. Your design should cover: - Product goals and success metr...
LLM Fundamentals: Tokenization Design and KL-Regularized SFT
LLM Fundamentals: Tokenization Design and KL-Regularized SFT You are interviewing for a research/ML role on a team that trains and fine-tunes large la...
First Word Matching Each Prefix Query
You are given a list of words (the dictionary) and a list of queries, where each query is a string prefix. For each query, return the index (0-based, ...
Hierarchical Access Control for an Advertising Platform
Design an access-control system for an advertising platform. Advertisers are organized into a hierarchy of groups. A group may contain other groups (s...
Check Whether a String Is Built by Repetition
Given a non-empty string s, determine whether it can be constructed by repeating one of its non-empty proper substrings two or more times. A proper su...
Implement one-cluster k-means
Given n points in d-dimensional space, implement k-means clustering with squared Euclidean distance for the special case k = 1. Return the single cent...
Search Monster Battle Strategies
You are given two teams of monsters. Each monster has: - hp: starting health - attack: damage dealt per attack - revive_hp: if greater than 0, the mon...
Build Ranked Feed With Photo Batching
You are given a list of feed objects. Each object has: - id: a unique string - type: one of Normal, Video, or Photo - score: a numeric ranking score C...
Wrap Matching Substrings in Bold Tags
During a machine learning engineer phone screen, the coding task was: You are given a string text and a list of strings patterns. Return a new string ...
Analyze sales with groupby
You are given three pandas DataFrames representing a food delivery marketplace: - orders(order_id, product_id, quantity, unit_price, status) - product...
ML System Design: Movie Recommendation Model and Pipeline (AI-Assisted Round)
ML System Design: Movie Recommendation Model and Pipeline (AI-Assisted Round) This is a hands-on, AI-assisted coding round: you are allowed to use AI ...
ML System Design: Thumbnail Selection for a Streaming Catalog
ML System Design: Thumbnail Selection for a Streaming Catalog You work at a video streaming service. For each title in the catalog (movie or show), th...
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...
Weighted Random Sampling by Index
Weighted Random Sampling by Index You are given an array of positive integer weights weights, where weights[i] is the weight assigned to index i. Impl...
Maintain a Streaming Median
You are designing a component that receives integers one at a time and must return the current median after each update. Example: - After processing [...
Solve matrix rotation and 1-D illumination
Question LeetCode 48. Rotate Image – rotate an n×n matrix 90° clockwise (extra space allowed). Find the point(s) with the maximum number of illuminate...