Interview questions

Design a Scalable, Polite Web Crawler

Companies: Snowflake

System Design · System Design Fundamentals

Last reported Oct 2026

Design an Online Devbox Service for On-Demand Cloud Development Environments

Companies: OpenAI

Containers & Orchestration · System Design · System Design Fundamentals

Last reported Oct 2026

Design a Log Ingestion System for a SIEM Server

Design a resilient log ingestion system that collects and forwards logs from a product to customers' SIEM instances, optimizing for high availability, fault tolerance, and…

Companies: Zscaler

Last reported Oct 2026

Design a Policy Delivery System for Cloud and Mobile Endpoints

Design a multi-tenant policy configuration and delivery system that allows administrators to define, manage, and distribute policies to nodes configured in the cloud as well…

Companies: Zscaler

Last reported Oct 2026

Design a Remote Code Execution (RCE) System

Design a remote code execution system similar to platforms like LeetCode, where users can write, submit, and execute code in multiple programming languages in a…

Companies: Oracle

Last reported Oct 2026

Design a Real-Time Trivia Battle Royale Platform with Live Spectating

Companies: OpenAI

Fault Tolerance & Failover · Multiplayer Game Systems · System Design

Last reported Oct 2026

Design a Risk Assessment Service for Order Purchases

Design a risk assessment service that enables the Buyer and Risk Prevention Team to automatically detect and evaluate potential risks during order purchases, including fraud…

Companies: Amazon, Payment Startup

Last reported Oct 2026

Design a Top-K System

Design a system that efficiently retrieves top-k items (songs, videos, hashtags, etc.) based on user activity or engagement metrics within specified time windows. The system…

Companies: Amazon, Atlassian, Bloomberg, eBay +10

Last reported Oct 2026

Design an ad click aggregator

High-volume event aggregation: duplicate delivery, hot ads, late events, fast window queries, and reconciling live counts with final billing totals.

Companies: Amazon, Google, Meta, Rippling +4

deduplication · event-time · hot-keys · reconciliation

Last reported Oct 2026

Design an Anti-Phishing System

Design an anti-phishing backend system for Chrome that intercepts navigation to malicious websites and shows users a warning page, while still allowing them to proceed…

Companies: Google

Last reported Oct 2026

Design an API gateway

A shared API entry point must enforce request policies, translate protocols, and isolate failures at high request rates.

Companies: Cisco, MongoDB

authentication · configuration-distribution · fault-isolation · protocol-translation

Last reported Oct 2026

Design an Inventory Service with Stock Reservations That Prevents Overselling

Companies: Instacart

System Design · System Design Fundamentals

Last reported Oct 2026

Design Recommender System

Design a recommendation system that analyzes user preferences and behavior to suggest relevant content, products, or services with personalized rankings and filtering capabilities.

Companies: Disney, Goldman Sachs, LinkedIn, Meta +1

Last reported Oct 2026

Design transient publish-subscribe messaging

Design a publish-subscribe messaging system where publishers can send messages to topics and subscribers can listen to those topics. Messages are lost if no subscribers…

Companies: Microsoft, Roblox

Last reported Oct 2026

Patch Storage Data-Plane Hosts, Roll Out Fixes, Keep New Hosts on the Latest Image

Companies: Oracle

System Design

Last reported Oct 2026

Design a Merchant Product Listing System

Design a system that allows merchants to create and manage product listings via single or bulk updates, while enabling regular users to browse and view…

Companies: Pinterest

Last reported Oct 2026

Design a Real-Time Multiplayer Typing Race with Typo Freezes and Fair Matchmaking

Companies: OpenAI

Distributed Coordination · Multiplayer Game Systems · System Design

Last reported Oct 2026

Design an AI-Agent Security Detection Pipeline for 1 TB/Day of Streaming Telemetry

Companies: Amazon

System Design · System Design Fundamentals

Last reported Oct 2026

Design a distributed rate limiter

Algorithm trade-offs (fixed window, sliding log, sliding counter, token bucket), placement, distributed atomic counting, failure modes.

Companies: Amazon, Anthropic, Apple, Freshworks +14

api-gateway · atomicity · Concurrency · Consistency & Availability

Last reported Oct 2026

Design a Log Processing and Alerting System

Design a system that ingests and processes logs from multiple services to extract useful insights, including the ability to track 5xx errors per service and…

Companies: Amazon, Apple, GitHub

Last reported Oct 2026

Design a Payment Reconciliation System

Design a payment reconciliation system that receives settlement files from multiple banks in varying formats and frequencies, reconciles them against recorded transactions from…

Companies: Okta

Last reported Oct 2026

Design a product likes system for a marketplace of brands and retailers

Companies: Faire

API Design · System Design · System Design Fundamentals

Last reported Oct 2026