Design a One-on-One Chat Service
Company: Anthropic
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Technical Screen
Design a scalable one-on-one chat service.
The service should allow registered users to exchange private text messages in real time across web and mobile clients. A user may be logged in from multiple devices. The system should support message delivery, message history, offline users, read receipts, and basic reliability guarantees.
Discuss requirements, APIs, data model, high-level architecture, real-time delivery mechanism, storage choices, scaling strategy, failure handling, and trade-offs.
Quick Answer: This question evaluates the ability to design a scalable, real-time one-on-one messaging service, probing distributed systems concepts, data modeling, API design, storage strategies, real-time delivery mechanisms, and reliability guarantees.