Meta Machine Learning Engineer Interview Questions
Meta Machine Learning Engineer interview questions typically probe both algorithmic skill and practical ML judgment. At Meta you should expect a mix of coding (data structures and algorithms), applied ML and modeling questions, ML-system design, and behavioral/leadership rounds that focus on impact, collaboration, and product thinking. What’s distinctive is the emphasis on production-ready thinking: interviewers evaluate how you translate models into scalable systems, choose metrics, reason about data and bias, and trade off latency, cost, and reliability in real-world settings. Recent pilots also include AI-assisted coding components in some interviews, so being fluent with modern developer workflows can help. For interview preparation, prioritize three threads: sharpen algorithmic coding (medium-to-hard problems), deepen practical ML fundamentals (evaluation metrics, debugging, feature engineering, model degradation), and practice end-to-end ML system design at scale (data pipelines, monitoring, deployment). Prepare STAR stories that show ownership and cross-team impact, and rehearse clear, structured explanations of trade-offs. Expect a timed loop of 4–6 focused interviews and a hiring committee review, so consistent performance across rounds matters more than a single standout answer.
Answer core behavioral questions using STAR
Prepare structured answers (use STAR: Situation, Task, Action, Result) for the following common behavioral prompts: 1. Most proud project: Describe a ...
Solve shipping capacity and expression insertion
Problem A: Minimum shipping capacity You are given an array weights where weights[i] is the weight of the i-th package. Packages must be shipped in or...
Design recommendation and weapon-ad detection systems
You are asked to design two end-to-end ML systems. 1) Personalized recommendation system Design a system that recommends items (e.g., videos/products/...
Compute nested depth sum and grid distance
Problem A: Weighted sum of integers in a nested list You are given a nested list structure that may contain integers or other nested lists. Define the...
Solve linked list, tree, and grid problems
Problem A — Find cycle entry in a singly linked list You are given the head of a singly linked list. The list may contain a cycle. - Return the node w...
Implement weighted random city and sparse dot product
Question 1: Weighted random city picker You are given a mapping from city → population (all populations are positive integers). Implement a random gen...
Design versioned in-memory key-value store
You are asked to design an in-memory key–value store that supports versioning and rollback. Requirements - Store key–value pairs in memory (string key...
Design concurrent expiring job registry
Design (and discuss how you would implement) an in-memory job registry that supports concurrent access. Each job has a unique jobId and an expiration ...
Architect an asynchronous RL post-training system
System Design: Asynchronous RLHF/RLAIF Post-Training for a Production Chat LLM Context You operate a chat LLM that already serves real user traffic. Y...
Design comment ranking for a news feed
Design an ML-powered system to rank comments under posts in a news feed product. Requirements - For each feed item (post/story), users can open the co...
Answer impact, conflict, and difficult coworker questions
Behavioral questions 1. Describe the most impactful project you have worked on. 2. Tell me about a difficult person you have worked with. 3. Describe ...
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...
Find kth smallest pair sum with heaps
You are given two nondecreasing arrays A (length n) and B (length m) of non-negative integers and an integer k (1 <= k <= n*m). Return the k-th smalle...
Optimize ribbon piece length by binary search
Given an array lengths of positive integers and an integer k, you may cut each element into pieces of integer length L > 0. Find the maximum L such th...
Detect cycles and order with DFS
You are given a directed graph of package dependencies represented as an adjacency list: Map<String, List<String>> deps where deps[p] lists packages t...
Design a scalable MoE pretraining pipeline
Design a Large-Scale MoE Pretraining Pipeline (Bilingual LLM, 1T Tokens, 256×A100-80GB) Context You are designing a pretraining pipeline for a decoder...
Describe learning from a post-interview bug
Behavioral Prompt: Bug Discovered After a Remote Technical Screen Context You are in a remote technical screen for a Machine Learning Engineer role. Y...
Check diagonal equality in a matrix
Given an m x n integer matrix, determine whether every top-left to bottom-right diagonal contains identical values (all elements along each such diago...
Solve matrix diagonal and sliding-window statistics
1) Given an m x n integer matrix, determine whether every top-left to bottom-right diagonal has the same value (Toeplitz property). Return true/false,...
Implement sliding-window moving average
Design a class MovingAverage that supports a constructor MovingAverage(k) and a method next(val) returning the average of the last k values from a dat...