Pinterest Interview Questions
Practice 124 real interview questions from Pinterest. Covers Coding & Algorithms, Analytics & Experimentation, Data Manipulation (SQL/Python), Machine Learning. For roles including Data Scientist, Software Engineer, Machine Learning Engineer, Data Analyst.
"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."
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...
Reconstruct route from unordered travel tickets
You are given a list of directed travel tickets, each represented as a pair [from, to] (city names are strings), e.g. [["A","B"],["B","C"], ...]. The ...
Implement Naive Bayes classifier from scratch
Implement a Naive Bayes classifier from scratch (you may use NumPy). Write a class with: - fit(X, y): estimate class priors and feature likelihood par...
Explain bias–variance, overfitting, and vanishing gradients
Answer the following ML fundamentals questions: 1. Bias–variance tradeoff: What are bias and variance? How do they relate to underfitting/overfitting?...
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 a violation log analyzer
You are given an append-only list of violation events as tuples (id: string, policy: string, date: ISO-8601 string). Build an in-memory "Violation Log...
Implement stream line reader and settle balances
Part 1: Streaming line reader from chunked source You are given an existing class ChunkSource with a method nextChunk() that returns the next piece of...
Implement sparse matrix storage, addition, and multiplication
Design a way to store a sparse matrix (most entries are zero) and implement efficient operations. You are given matrices using their non-zero entries:...
Generate all hyperparameter combinations
You are given several groups of hyperparameter choices for an ML experiment. Each group contains one hyperparameter name and a list of candidate value...
Implement and extend My Calendar III
Design and implement a booking system like LeetCode 732 (My Calendar III). Provide a class with methods: book(start, end) using half-open intervals [s...
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...
Design an ads system to improve CTR
Design an ML system to increase the click-through rate (CTR) of ads shown in the feed of an online social media platform. Address the following: 1. Go...
Compute percent of first-cancelled users who never rebook
You are interviewing for a health-tech product analytics role. Assume the following table contains one row per appointment with its final status. Tabl...
Design autocomplete and merchant bulk edits
System Design Prompts 1) Design search engine input suggestions (autocomplete) Design a system that provides real-time query suggestions as a user typ...
Write Queries for Pinterest Engagement Tasks
You are given several data-manipulation tasks based on Pinterest-style product data. Use UTC for all timestamp-to-date conversions unless stated other...
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...
Solve a 9x9 Sudoku puzzle
Given a partially filled 9×9 Sudoku board, fill the empty cells so that the completed board is valid. A valid Sudoku satisfies: - Each row contains di...
Implement bagging with decision trees
Implement a simple bagging (bootstrap aggregating) classifier that uses decision trees as base learners. You are given a template with a DecisionTree ...
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...
Write SQL for top categories and highly active users
You are given three tables: 1) impression Event-level table of user impressions. - impression_id BIGINT (PK) - user_id BIGINT (FK → user.user_id) - pi...