Pinterest Interview Questions
Practice 125 real Pinterest interview questions for 2026. Covers all top categories — Coding & Algorithms, Data Manipulation (SQL/Python), Analytics & Experimentation, Machine Learning, System Design — across Data Scientist, Software Engineer, Machine Learning Engineer, and Data Analyst roles. Real questions from actual interviews with detailed solutions. This collection leans hard on coding and algorithm problems for SWE candidates while giving equivalent weight to experiment design, SQL/Python analytics, and model evaluation for data roles, making it a focused resource for interview preparation for screens, virtual onsites, and take-home assignments. Expect interviews to evaluate algorithmic thinking, production design, experimental rigor, and clear data storytelling. For Data Scientists you’ll see carousel and billboard lift evaluation, weighted/random-sampling implementations, numpy/pandas and SQL analytics on category and video-time metrics, and survey-balance diagnostics. Software Engineers face prefix-matching, catalog update pipelines, sparse-matrix ops, grid/graph puzzles, and ads event reporting or blob storage design. Machine Learning Engineers get pin-search and recommender design, Naive Bayes/bagging implementation, hyperparameter generation, and sampling-by-score problems. Data Analysts encounter cohort and cancellation/rebooking metric questions. Prepare with timed coding drills, end-to-end A/B case studies, polished Python/SQL practice, and concise STAR stories for behavioral rounds.
"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."
Decide if ad load is optimized
Pinterest Home Feed Ad Load Optimization You are asked to design an analysis and experiment to determine whether the current home-feed ad load (ads pe...
How to evaluate a new Carousel feature
Context You are a Data Scientist at Pinterest. The product team wants to add a horizontal Carousel module at the top of the Home feed (similar to an I...
Design Hierarchical Permission Checks
You are given a hierarchy of groups represented as a tree, for example World -> Country -> City. Each advertiser can be granted access at any group no...
Decide target via subsequence plus/multiply expression
Question Given a sequence of positive 32-bit integers A and an integer target, determine whether there exists a subsequence of A (preserving order, us...
Support room moves and query top-k fastest
Problem There are R rooms labeled 0..R-1 (in increasing order), and P people labeled 0..P-1. - Initially, all people are in room 0. - Operation move(p...
Settle debts with minimal transactions
You are given a list of debts among a set of people, expressed as triples (debtor, creditor, amount) (equivalently (payer, payee, amount)), where each...
Explain overfitting and how to prevent it
You are asked rapid-fire ML fundamentals questions. 1. What is overfitting? Explain it in terms of training vs. validation performance and generalizat...
Design Detection Systems for Risk and Safety
The machine learning system design rounds focused on designing end-to-end production systems for several detection problems: 1. Bank fraud detection: ...
Answer core ML fundamentals questions
You are asked several short ML fundamentals questions: 1) Define precision and recall for a binary classifier and explain how they relate to a confusi...
Design and Evaluate a Home Carousel
Pinterest is considering adding a horizontally scrollable carousel at the top of the Home feed, similar to Instagram Stories. The carousel may surface...
Explain overfitting, underfitting, and regularization
You are asked ML fundamentals questions. 1. What are overfitting and underfitting? Describe how they show up in training vs. validation/test performan...
Assign Pins to Shortest Columns
You are given a list of pins, where each pin has a height, and a fixed number of columns in a masonry-style layout. Process the pins in their original...
Determine equality of arbitrarily nested sets
Implement a function that determines whether two arbitrarily nested sets are equal. Sets are unordered and contain no duplicates; elements can be inte...
Design and assess a video-pin increase experiment
Question Pinterest wants to increase the share of video pins surfaced in the Home Feed (e.g., raising video share from a ~30% baseline toward a 45% ta...
Implement string-based rounding without floats
Coding You are not allowed to parse the input into a built-in floating type (to avoid overflow and precision issues). Work directly on strings. 1) Imp...
Design an ads system to improve CTR
Design an ML system to increase the click-through rate (CTR) of ads shown in the personalized feed of an online social media platform. You run the ran...
Find First Prefix-Matching Word
Given an array of strings words and a prefix string prefix, return the smallest index i such that words[i] starts with prefix. If no word matches, ret...
Implement a min-heap column allocator
You are given an integer k (number of columns) and an array posts of positive integers where posts[i] is the height of the i-th post. All columns star...
Implement tap-to-infect color grid on iOS
iOS Grid Infection (Flood Fill) Design Goal Build an iOS app that displays a 2D grid with two colors. When the user taps a cell, all 4-directionally a...
Cross-reference logs to flag spam numbers
You are given two data sets: ( 1) a call log containing phone numbers observed in calls and ( 2) a list of user reports where each entry is a phone nu...