Meta System Design Interview Questions
Practice 1,159 real Meta interview questions for 2026. Covers top categories — Coding & Algorithms, Analytics & Experimentation, Data Manipulation (SQL/Python), Behavioral & Leadership, and System Design — across Software Engineer, Data Scientist, Machine Learning Engineer, Data Engineer, and Product Manager roles. Real questions from actual interviews with detailed solutions. Expect a software-engineering-heavy loop: timed algorithmic coding (trees, arrays, graph/maze problems, delimiter/CSV parsing), system-design prompts like leaderboards, flight search and online-judge architectures, and an increasingly common AI-assisted coding round that mirrors real workflows. Data Scientist rounds emphasize product analytics and experimentation—designing tests, diagnosing spend drops and bots, evaluating unconnected content, and writing SQL for multi-account, seller, and vehicle metrics. Machine Learning Engineer questions skew toward recommender and ranking work (place and friend recommendation, sparse-matrix ops, linear-regression derivations, newsfeed dislike models). Data Engineers focus on data modeling, ETL, capacity calculations, reservations/utilization queries, and production SQL/Python tasks. For interview preparation, prioritize timed coding practice, system-design templates, rigorous SQL drills (joins/CTEs/aggregation), clear A/B-testing frameworks, and concise STAR behavioral stories tied to measurable impact.
"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."
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"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."
Estimate first selection round with/without replacement
This question evaluates understanding of probability and expectation concepts, specifically sampling with and without replacement, per-round success p...
Diagnose sales correlations without claiming causality
This question evaluates a data scientist's competency in designing correlation-focused observational analyses, including exposure-window definition, c...
Measure notification impact and set guardrails
This question evaluates causal inference, experiment design, metric specification and attribution, statistical power calculation, and long-term monito...
Identify latent group-call demand from behavior
This question evaluates a data scientist's ability to design measurable product-analytics signals, infer latent user demand from event-level messaging...
Estimate and validate weights for engagement actions
This question evaluates statistical modeling and inference skills including constrained weighting, uncertainty quantification, multicollinearity and s...
Design and justify unread-account pinning experiment
This question evaluates a data scientist's competency in experimental design, causal inference, metric definition, instrumentation, and analysis for p...
Design and analyze notification pinning experiment
This question evaluates experimental design, causal inference, metric definition and instrumentation, sample size estimation, and analysis skills in t...
Determine if users need a new feature
This question evaluates a data scientist's competency in product analytics, causal inference, experiment design, metric definition, instrumentation, a...
[Analytical Reasoning] Comparing Two Newsfeed Ad Insertion Methods
Compare two ad-insertion methods for a 100-post newsfeed. Both methods have the same average ad load. - Method A: each post is independently replaced ...
[Analytics Reasoning] Impact of Malicious Accounts on Meta
You are analyzing malicious accounts on a large social network. Assume: - 1% of all accounts are malicious. - Malicious accounts send friend requests ...
Design an e-commerce price tracking service
Design a backend system for an e-commerce price-tracking service. Users can track products from a large online retailer, view historical prices, and r...
Solve sliding window and tree BFS problems
1) Sliding window: Given an array of positive integers nums and an integer target, return the minimal length of a contiguous subarray whose sum is at ...
Count palindrome substrings in a string
Given a lowercase ASCII string s, count the number of substrings that are palindromes and return the count. Implement an O(n^ 2) solution using expand...
Design scalable media storage and delivery
System Design: Global UGC Photos and Short Videos Store/Delivery Context Design a globally distributed system to store and deliver user-generated phot...
Compute nested depth-weighted sum
You are given a nested structure containing integers and lists (e.g., [1, [4, [6]]]). Define depth of the top-level as 1. Compute the total sum of all...
Solve grid path and top‑k frequency
Part A — Grid Reachability with Obstacles: Given an m×n matrix of 0s and 1s where 0 indicates a passable cell and 1 indicates a blocked cell, starting...
Handle invalid input at system level
Design: Validation and Error Handling for a Top-K Frequency API Context You are designing a REST endpoint that computes the top-K most frequent values...
Compute capacities after site closures
You are given a nested dictionary redistribution where redistribution[closed_site][dest_site] equals the additional capacity required at dest_site if ...
Compute vertical order of a BST
Compute the vertical order traversal of a binary search tree. Define coordinates so the root is at column 0, row 0; the left child is (col−1, row+ 1) ...
Implement bounds, minimum, pathfinding, and moving average
Solve the following data-structures problems: ( 1) Given two sorted integer lists A and B, merge them into a single non-decreasing array. Then, for a ...