#chat

9 chat interview questions, asked at Anthropic, OpenAI, Google and 8 more companies. Last asked Oct 2026.

One-on-one chat system with presence and offline queueSystem designDesign direct messaging between two users, where each user is on a single device. Messages to an online recipient arrive in real time; messages to an offline recipient are kept…
Last asked Oct 2026
+6
Design an AI chatbot appSystem designDesign an AI assistant chatbot web app built on a hosted LLM API. A signed-in user starts conversations, types a message, and sees the model's answer stream back token by token…
Last asked Oct 2026
+4
Design ChatGPTSystem designDesign a consumer chat product backed by a large language model: conversations, streamed replies, history across devices, at 100M weekly users.
Last asked Sep 2026
+7
Design a Slack-like chat systemSystem designDesign a Slack-like team chat system for large companies: workspaces with channels, threads and direct messages, real-time delivery to online clients, unread state, history and…
Last asked Sep 2026
+5
Design Facebook MessengerSystem designDesign Facebook Messenger: one-to-one and group messaging for about a billion users, with real-time delivery, offline sync, delivery and read receipts, and full message history on…
Last asked Sep 2026
Design ChatGPT streaming with resumable responses and long conversationsSystem designYou have sketched a ChatGPT-style chat product. Now go deeper on three parts: how replies stream to the browser, how a reply survives the client disconnecting mid-stream and…
Last asked Jul 2026
Design customer support with handoff from virtual agent to humanSystem designUsers chat with a virtual agent (a bot) and can be escalated to a human support agent. Design the system, with the focus on the handoff: how the conversation's context goes with…
Last asked Jul 2026
Design a multi-agent chat backendSystem designThe interviewer demos a simple ChatGPT-style chat UI used by customers of a financial product. Your scope is the backend behind it. A user sends a message and gets a streamed…
Last asked Jun 2026
Design an embeddable streaming chat interfaceSystem designFor a frontend role: design a chat widget for an AI agent that other products can embed in their pages. The agent's replies stream in as they are generated. Cover how the widget…
Last asked Apr 2026