Interview questions

Design a Chargeback System for Fraud Transactions

Design a chargeback system that allows customers to report fraudulent charges. The system should optimistically approve chargeback requests and then batch process them when…

Companies: Nubank

Last reported Oct 2026

Design a User Behavior and Metrics Monitoring Aggregator

Companies: Rippling

Observability · System Design

Last reported Oct 2026

Design a Job Queue for Multi-Stage Jobs on GPU and CPU Clusters

Companies: Nuro

System Design

Last reported Oct 2026

Design a Medical Sensor Monitoring and Control System

Design a large-scale control system capable of monitoring and managing up to 1 million sensors in a medical or hospital setting, supporting real-time data collection…

Companies: OpenAI

Last reported Oct 2026

Design a polling system

Design a polling system that allows users to create polls with multiple options, vote on existing polls, and view real-time voting results.

Companies: Figma, Upstart

Last reported Oct 2026

Design an Online Bookstore

Design a system for selling physical books through a website that allows users to browse catalogs, search for books, make purchases, and manage inventory.

Companies: Amazon, Databricks, JPMorgan Chase

System Design · System Design Fundamentals

Last reported Oct 2026

Design Food Reviews with a Reward Workflow

Companies: DoorDash

System Design · System Design Fundamentals

Last reported Oct 2026

Generate and Reuse Invoices on Demand for a Customer and Time Range

Companies: Atlassian

API Design · System Design · System Design Fundamentals

Last reported Oct 2026

Design a ChatGPT-style chat service with streaming model replies

Companies: OpenAI

LLM Applications · Real-Time Systems · System Design

Last reported Oct 2026

Design a Delayed Job Scheduler

Companies: Decagon

System Design

Last reported Oct 2026

Design a Cloud Browser Automation Agent Platform (Cloud Operator)

Design a cloud-based AI agent platform that allows users to start a session with a prompt, where the agent autonomously uses a cloud-hosted browser to…

Companies: OpenAI

Last reported Oct 2026

Design a Loan Payment Processing System

Design a system that allows customers to submit payment intents and securely collect and process their regular loan payments.

Companies: Affirm

Last reported Oct 2026

Design a Financial Reporting Service

Design a financial reporting service that allows users to generate reports within a specified date range, view or download those reports, with each report automatically…

Companies: Microsoft

Last reported Oct 2026

Design a Food Order and Delivery Tracking System

Companies: Amazon

System Design

Last reported Oct 2026

Design a Peer-to-Peer Financial Application

Design a peer-to-peer financial application similar to Cash App that allows users to send and receive money, manage their balance, and process transactions with strict…

Companies: Block

Last reported Oct 2026

Design a warehouse management system

Physical stock and digital records must agree while workers receive, move, pick, and pack goods at the same time.

Companies: Amazon, Coupang, Procore

concurrency · inventory · physical-reconciliation · request-retries

Last reported Oct 2026

Design an IP Blocking Service Backed by a Slow, Unreliable Government API

Companies: Remitly

System Design

Last reported Oct 2026

Design an ISP Bandwidth Limiter

Design a bandwidth limiting system used by Internet Service Providers (ISPs) to enforce client subscription limits, such as capping network throughput to a purchased tier…

Companies: Google

Last reported Oct 2026

Design Scheduler Claims, Execution Guarantees, and Recovery

Companies: NVIDIA

System Design

Last reported Oct 2026

Design a Food Review System for a Delivery App, Focused on the Database Schema

Companies: DoorDash

System Design

Last reported Oct 2026

Design a Real-Time Multiplayer Typing Race Game

Companies: OpenAI

Multiplayer Game Systems · Real-Time Systems · System Design

Last reported Oct 2026

Design a Rule Management Service for AI Agents with Drafts, Publishing and Rollback

Companies: Decagon

API Design · System Design

Last reported Oct 2026