Project Objective

• Improve an existing chat system by integrating real-time voice calling and voicemail functionalities.
• Ensure seamless messaging and call experience between users with low latency and reliable reconnection strategies.

Technical Stack & Architecture

• Frontend: Next.js for UI and WebRTC for peer-to-peer audio streams.
• Backend: Node.js with Socket.io for signaling and real-time message exchange; MongoDB for message/voicemail storage.
• Services: Twilio (voice) for PSTN/inbound/outbound call handling and voicemail integration.

Responsibilities & Tasks

• Implement WebRTC-based voice call setup and media handling within the Next.js application.
• Integrate Socket.io signaling on backend (Node.js) to manage call/session negotiation, presence, and messaging events.
• Build voicemail recording, storage in MongoDB, and playback mechanisms; connect voicemail storage with Twilio when required.
• Handle error cases, reconnection logic, NAT traversal (STUN/TURN), and call state synchronization between clients and server.

Non-functional Requirements

• Low latency and robust reconnection behavior for voice calls and messaging.
• Proper handling of concurrent sessions, message ordering, and delivery acknowledgements.
• Basic security considerations for media and signaling channels (use HTTPS/WSS, secure session tokens).

Expected Deliverables

• Working Next.js frontend demonstrating text chat, one-to-one voice call, and voicemail playback UI flows.
• Node.js + Socket.io backend implementing signaling, message delivery, and voicemail API endpoints; MongoDB schema for messages/voicemails.
• Integration tests or manual test plan demonstrating call setup, teardown, voicemail recording/playback, and edge cases.

Skills & Qualifications

• Experience with React/Next.js and WebRTC concepts (getUserMedia, RTCPeerConnection, ICE candidates).
• Familiarity with Node.js, Socket.io, and MongoDB; ability to design simple REST/WebSocket APIs.
• Experience integrating third-party voice services (Twilio) is a strong plus.

How to apply

• Send your CV, a short motivation, and links to any relevant projects or demos to issam@code-reason.com.
• Email subject: "Application for Real-Time Chat with Voice Call and Messaging PFE"