Real-Time Chat Application

A horizontally scalable messaging platform tuned for high concurrency and persistent messaging.

Key Features

• Group and direct channels, each with granular permission policies.
• Typing indicators, read receipts, and presence tracking backed by Redis.
• File and media sharing routed through signed AWS S3 URLs.
• Searchable history with message retention controls per workspace.

Architecture Overview

Messages are published through a gateway using WebSockets. Redis pub/sub fans updates out to workers that handle persistence in MongoDB. Background jobs archive older messages to S3 and keep the search index fresh.

Local Development

1. terminal

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   pnpm install
2. Copy
   terminal

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   .env.example
   to
   terminal

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   .env
   and configure Redis, MongoDB, and S3 credentials.
3. Run
   terminal

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   pnpm dev
   to start both the API and client using turborepo pipelines.

Deployment Tips

• Scale horizontally by increasing the number of API pods; sticky sessions are not required thanks to Redis.
• Enable autoscaling alerts to detect spikes in fan-out operations.
• Rotate encryption keys regularly; the key schedule is handled by AWS KMS.