MyMapChat Application System Design
A system design diagram for a real-time chat application with WebSocket servers, Redis pub/sub, Kafka message queue, PostgreSQL, S3, and Elasticsearch.
Preview
“Create a system design diagram for a chat application”
About the framework
System Design for Real-Time Chat
This template addresses the core system design interview question of building a scalable chat application. The architecture solves three key challenges: real-time delivery (WebSocket + Redis pub/sub), reliable persistence (Kafka + PostgreSQL), and media handling (S3).
Redis pub/sub bridges multiple WebSocket servers so a message sent through Server 1 reaches a recipient connected to Server 2. Kafka provides at-least-once delivery guarantees and decouples the write path from storage and notification services.
Customize by adding read receipts, typing indicators, group chat logic, or end-to-end encryption layers. You can also scale specific components, like adding Cassandra for message storage at WhatsApp-level scale.
What's included
What you get
- Multi-tier architecture with 12 service nodes
- Client layer: Mobile/Web with Load Balancer routing
- Real-time: WebSocket servers with Redis pub/sub for cross-server messaging
- Async: Kafka queue for message persistence and fan-out
- Storage: PostgreSQL, S3 media, Elasticsearch for search
Chat Application System Design
Frequently asked questions
Common questions
Can I simplify this for a smaller-scale app?
Yes. Click 'Use this template' and ask 'Simplify to a single WebSocket server with PostgreSQL only.' The AI will remove Kafka and Redis for a simpler architecture.
How do I add end-to-end encryption?
Ask the AI to 'Add a key exchange service and show the E2E encryption flow between clients.' It will insert a key management component and update message flow.
Can I use this for a system design interview?
Absolutely. This covers the standard components interviewers expect. Ask 'Add capacity estimation annotations showing messages per second and storage requirements' for interview-ready detail.
Chat Application System Design
Free to start. No credit card required.