MERN Stack Developer - Conversational AI Platform

Company Description

CallSphere LLC is revolutionizing retail with conversational AI that lets customers place orders naturally through both voice calls and text-based chatbots. Our platform handles product discovery, order processing, and customer support end-to-end in real time. We’re piloting with small and mid-sized retailers and continually improving semantic search accuracy, agentic workflows, and natural, human-like interactions. Join us to deliver faster, more intuitive buying experiences.

Role Description

This is a remote unpaid post-OPT full-time role for a MERN Stack Developer. You’ll build and maintain the web application, APIs, data systems, and internal tools that power CallSphere’s voice agents and agentic chatbots. Work includes building dashboards, integrating with AI and telephony/chat APIs, designing secure backend services, managing product/order data models, and supporting real-time conversational experiences.

Qualifications

• Strong proficiency in JavaScript/TypeScript and MERN stack development (MongoDB, Express.js, React/Next.js, Node.js).
• Experience building REST APIs, authentication workflows, and integrating external AI/communication services.
• Familiarity with APIs for calls, SMS/WhatsApp, or chat (e.g., Twilio, Meta/WhatsApp Cloud API).
• Understanding of integrating AI systems such as ASR, TTS, LLM inference, and chatbot events into backend pipelines.
• Solid database design skills (indexing, aggregation, performance) across MongoDB and SQL when needed.
• Ability to analyze system logs, debug conversational flows, and improve performance and reliability.
• Experience with Git/GitHub, CI/CD basics, and cloud deployment (AWS/GCP/Azure/Vercel/Render).
• Plus: real-time systems (WebSockets/Socket.IO), POS/payment integrations, or internal dashboard development.
• Soft skills: ownership, problem-solving, clear communication, async collaboration, and comfort working independently.

OPT/CPT sponsorship is available.