If you want a 100% self-hosted, scalable, real-time chat app that can handle 10M+ users, then MongoDB alone is not enough. You need a hybrid setup that balances speed, scalability, and real-time performance.
| Component | Technology | Why? |
|---|---|---|
| Primary DB (User Data, Chats, Groups, Metadata) | PostgreSQL (or MySQL) | Structured, reliable, scalable, great for ACID compliance |
| Chat History Storage (Messages, Media Links) | MongoDB | Flexible schema, sharding, stores large chat logs |
| Real-Time Messaging | Redis (Pub/Sub) + WebSockets (Socket.io) | Fast, low-latency, perfect for instant delivery |
| Message Queueing (Offline Delivery, Scaling WebSockets) | Apache Kafka / NATS | Handles millions of messages per second, ensures message persistence |
| Mobile-Optimized Realtime (Alternative to WebSockets) | MQTT (Eclipse Mosquitto, EMQX, VerneMQ) | Lightweight, energy-efficient, used by WhatsApp |
| Media Storage (Images, Videos, Files) | MinIO (Self-hosted S3) | Self-hosted S3 alternative, avoids AWS dependency |
| Push Notifications (Self-Hosted Alternative) | Gotify / ntfy.sh / Firebase FCM | Sends alerts without cloud reliance |
| End-to-End Encryption | Signal Protocol (libsignal) | Secure, WhatsApp uses this |
✅ PostgreSQL → Users, groups, chat metadata
✅ MongoDB → Chat history, messages
✅ Redis (Pub/Sub) → Real-time message delivery
✅ Kafka/NATS → Offline messages, scalability
✅ WebSockets (Socket.io) + MQTT → Live updates
✅ MinIO (Self-Hosted S3) → Store images & media
✅ Signal Protocol (libsignal) → Encrypt messages
✅ 100% Self-Hosted – No reliance on Firebase, AWS, or Google services
✅ Massive Scalability – Works even if you scale to 100M+ users
✅ Optimized for Speed – Redis & Kafka ensure instant message delivery
✅ Privacy-Focused – Signal Protocol for end-to-end encryption
✅ WhatsApp/Telegram-Like Performance – Uses a proven architecture
If you want a 100% self-hosted, scalable, real-time chat app that can handle 10M+ users, then MongoDB alone is not enough. You need a hybrid setup that balances speed, scalability, and real-time performance.
| Component | Technology | Why? |
|---|---|---|
| Primary DB (User Data, Chats, Groups, Metadata) | PostgreSQL (or MySQL) | Structured, reliable, scalable, great for ACID compliance |
| Chat History Storage (Messages, Media Links) | MongoDB | Flexible schema, sharding, stores large chat logs |
| Real-Time Messaging | Redis (Pub/Sub) + WebSockets (Socket.io) | Fast, low-latency, perfect for instant delivery |
| Message Queueing (Offline Delivery, Scaling WebSockets) | Apache Kafka / NATS | Handles millions of messages per second, ensures message persistence |
| Mobile-Optimized Realtime (Alternative to WebSockets) | MQTT (Eclipse Mosquitto, EMQX, VerneMQ) | Lightweight, energy-efficient, used by WhatsApp |
| Media Storage (Images, Videos, Files) | MinIO (Self-hosted S3) | Self-hosted S3 alternative, avoids AWS dependency |
| Push Notifications (Self-Hosted Alternative) | Gotify / ntfy.sh / Firebase FCM | Sends alerts without cloud reliance |
| End-to-End Encryption | Signal Protocol (libsignal) | Secure, WhatsApp uses this |
✅ PostgreSQL → Users, groups, chat metadata
✅ MongoDB → Chat history, messages
✅ Redis (Pub/Sub) → Real-time message delivery
✅ Kafka/NATS → Offline messages, scalability
✅ WebSockets (Socket.io) + MQTT → Live updates
✅ MinIO (Self-Hosted S3) → Store images & media
✅ Signal Protocol (libsignal) → Encrypt messages
✅ 100% Self-Hosted – No reliance on Firebase, AWS, or Google services
✅ Massive Scalability – Works even if you scale to 100M+ users
✅ Optimized for Speed – Redis & Kafka ensure instant message delivery
✅ Privacy-Focused – Signal Protocol for end-to-end encryption
✅ WhatsApp/Telegram-Like Performance – Uses a proven architecture
| Component | Best Choice for You (JS-Friendly) |
|---|---|
| Backend | Node.js (Express / Fastify) |
| Real-Time Messaging | WebSockets (Socket.io) + Redis Pub/Sub |
| Database | PostgreSQL (Users/Groups) + MongoDB (Messages) |
| Message Queue | Kafka or NATS Streaming |
| Mobile Optimization | MQTT (for efficient messaging) |
| Frontend (Web) | React.js or Next.js |
| Frontend (Mobile) | React Native |
| Encryption | Signal Protocol |
| File Storage | MinIO (Self-hosted S3) |
| Push Notifications | Gotify (Self-hosted alternative to FCM) |