Design Real-Time Chat Application (Slack/Discord) - Frontend System Design Interview Guide
Hard•
Design a production-ready real-time chat application like Slack, Discord, or Microsoft Teams with channels, direct messages, presence indicators, and rich media support.
Backend as Black Box: Assume you have APIs for messages and real-time updates. Focus on the frontend architecture.
Key Challenges
This problem explores real-time communication challenges:
- Message Delivery: Send, receive, and sync messages reliably
- Message States: Sent → Delivered → Read with visual indicators
- Presence System: Online/Away/Offline status with typing indicators
- Offline Support: Queue messages, sync on reconnect
- Rich Content: Attachments, embeds, reactions, threads
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