Meta System Design Interview Questions
Practice 1,129 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"

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"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."

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"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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"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."
Measure and mitigate notification spam
Facebook sends many notification types (e.g., friends' posts, comments, birthdays, events). Design a rigorous measurement plan to determine whether ou...
Size opportunity and prioritize experiments
New E‑commerce Product Line: Pre‑Investment Quantification and Test Plan You are evaluating whether to invest engineering and operational resources to...
Select and prioritize metrics with guardrails
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Write SQL for engagement and attribution KPIs
Using the schema and sample data below, answer the SQL tasks. Assume timestamps are UTC and comments with is_deleted=1 do not count. Schema: users(use...
Brainstorm how to optimize email engagement
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Deliver an elevator pitch and impact example
Elevator Pitch + End-to-End Experimentation Case + “Why Meta?” Context You are interviewing for a Data Scientist role during a technical screen. Use c...
Compute daily post success rate for last 7 days
You have a table composer(user_id INT, event STRING CHECK(event IN ('enter','post','cancel')), event_date DATE). Compute the post success rate for eac...
Diagnose a sudden KPI drop and validate causes
A core KPI (comments_per_DAU) suddenly drops materially. Outline a structured root-cause analysis and validation plan. a) Scoping and sanity: Quantify...
Quantify launch decision with tests and guardrails
You will formalize the statistical decision rules for the Instagram button experiment described above. Given: baseline exploration rate (p0) = 0.15 pe...
Write SQL with HAVING and efficient joins
You are given two tables. Schema - interactions(product_id INT, buyer_id INT, seller_id INT, interaction_date DATE, interaction_type VARCHAR, interact...
Compute French DAU video-call percentage yesterday
Compute the percentage of daily active users (DAU) from France who were on at least one video call yesterday (2025-08-31 UTC). DAU is defined as users...
Compute callers contacting >3 people last 7 days
Using the schema below, write a single SQL query to return the number of unique callers who started calls with more than 3 distinct other users during...
Write SQL to analyze Group Calls adoption
Write SQL (assume PostgreSQL) to analyze Group Calls adoption and cannibalization. Use this schema and sample data. Schema: - users(user_id INT PRIMAR...
Validate needs and benchmark competitor adoption
Research Plan: Validate User Needs and Benchmark Competitors' Adoption of Group Calling You are designing a research plan for a consumer communication...
Choose group-call size cap via experiment
Decide the Maximum Participants per Group Call: Experiment Plan Context: You need to choose a default cap for group calls (maximum concurrent particip...
Write SQL for initiators and French DAU%
You are given the following PostgreSQL tables. Assume all timestamps are UTC and "today" is 2025-09-01. For any reference to "last 7 days," use the in...
Design a small-sample launch experiment in Europe
Launch Test Design: Early-Access EU Businesses Context You have an early-access pool of 1,200 EU businesses for a new chat subscription offering. Chat...
Justify EU B2B Chat Product Strategy
Executive Brief Task: EU B2C Customer-Service Chat (Subscription) Context You are asked to prepare a one-page executive brief recommending whether to ...
Write SQL for comment analytics
You are given the following schema and tiny sample data. Schema: - users(user_id INT PRIMARY KEY, country VARCHAR, created_at DATE) - posts(post_id IN...
Analyze regression to mean in heavy-tailed shares
Cohort Dynamics of a Right-Skewed Daily Shares Metric Context - You have a right-skewed metric: daily shares per user, with a long tail. - On Day 1, y...