Pinterest Software Engineer Interview Questions
Expect Pinterest Software Engineer interview questions to span algorithmic coding, system design (increasingly Pinterest-specific cases like feed, visual search, or ranking), and behavioral/product-sense conversations. What’s distinctive about Pinterest interviews is the product-context focus: interviewers often evaluate how you reason about user-facing ranking, relevance, and scalability tradeoffs in addition to core CS fundamentals. The process is typically structured and recruiter-led, with an initial screening step followed by several technical and behavioral rounds; senior roles place heavier weight on architecture, leadership, and cross-team impact. Interviewers evaluate problem solving, code clarity, system-level thinking, and collaboration/ownership. For interview preparation, balance algorithm practice (medium-to-hard problems and clean, testable code) with one or two mock system-design cases framed around feed, search, or recommendation systems. Prepare concise STAR stories that show measurable impact and learning, and be ready to discuss tradeoffs, metrics, and how you would instrument and iterate on a feature. Practicing pair-programming aloud and rehearsing product-oriented explanations will help you demonstrate both technical depth and the “Pinterest-y” product mindset.
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:...
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 ...
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...
Solve set equality and ad log top‑K
Problem Set (Coding) 1) Check whether two sets are equal You are given two integer arrays A and B that represent sets, except they may contain duplica...
Design highly available blob storage service
Design a large-scale, highly available blob storage service similar to Amazon S3. The service should allow clients to store, retrieve, and delete arbi...
Design a global high-throughput rate limiter
System Design: Global, High-Throughput Rate Limiter Context You are designing a global, multi-region rate-limiting service that enforces quotas: - Per...
Round numeric string values
Question Given a numeric string, implement rounding to the nearest integer (e.g., '3.5' → '4', '100.01' → '100'). Follow-up: round to the last signifi...
Reconstruct itinerary with lexicographic ties
You are given m airline tickets as directed pairs [from, to]. Build an itinerary that starts at a specified airport start (e.g., "JFK") and uses every...
Design ID allocator with resizable bucket ranges
Given a fixed global ID space [0, 999] and an initial list of bucket specifications, where each bucket has a unique name and an inclusive ID range [st...
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...
Demonstrate culture fit with examples
Behavioral & Leadership Interview (Software Engineer Onsite) You are preparing for an onsite behavioral and leadership interview for a Software Engine...
Implement string-based big integer multiplication
Implement multiplyStrings(a, b) to multiply two non-negative integers given as decimal strings and return the product as a string without converting t...
Decide target via subsequence plus/multiply expression
Given a sequence of positive 32-bit integers A and an integer target, determine whether there exists a subsequence of A (preserving order, using each ...
Implement string-based integer multiplication
Given two non-negative integers represented as decimal strings, return their product as a decimal string without using built-in big-integer or arbitra...
Determine subsequence expression equals target
Question Given a sequence of positive 32-bit integers A and an integer target, determine whether there exists a subsequence of A (each element used at...
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...
Design a high-throughput distributed rate limiter
System Design: High-Throughput Distributed Rate Limiting Service Context You are designing a multi-tenant rate limiting platform for an edge/gateway l...
Design a Google Photos–like service
System Design: Google Photos–like Service (Web + Mobile) Context Design a large-scale consumer media service that ingests, stores, indexes, and serves...
Design Pin recommendation system
System Design: Pin’s Home Feed Recommendation System Context You are designing an end-to-end recommendation system for Pin’s personalized home feed at...
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...