Backend Engineer

About the job

Location : Noida (Onsite) | Experience : 3-5 Years | 🚀 The Mission We are not looking for a Data Scientist who trains models in a notebook. We are looking for a Backend Engineer who builds real-time, bi-directional Voice AI agents. You will build the "Brain and Ears" of our fintech voice bots, ensuring they can listen, think, and speak in under 800ms. 🛠 What You Will Actually Build (Responsibilities) • The Pipeline : Architect full-duplex voice pipelines using WebSockets (not just REST APIs). Connect Twilio / Exotel streams to Deepgram / Whisper and LLMs in real-time. • The Speed : Optimize Python code using asyncio to handle concurrent calls. If the bot lags, you fix it. • The Logic : Move beyond simple "Chatbots." Build complex state machines (e.g., If user says 'Wait', stop talking immediately) using tools like LangChain or custom Python logic. • The Stack : Integrate best-in-class Voice APIs (Deepgram, Google TTS, OpenAI Realtime API) and deploy them on AWS / GCP using Docker. ✅ The "Must-Have" Tech Stack If you don't have these, please do not apply. • Python Frameworks : Mastery of FastAPI or Starlette. (Experience with only Django / Flask is not sufficient). • Real-Time Protocols : Deep understanding of WebSockets (wss://) and streaming audio data (bytes handling). • Concurrency : Proven experience with Async / Await (asyncio) in Python. You must know how to handle non-blocking I/O. • Voice Tech : Hands-on experience with ASR (Whisper, Deepgram, Google) and TTS (ElevenLabs, Azure, Polly). • LLM Integration : Experience building products with OpenAI API / Anthropic (Function Calling, System Prompts, JSON Mode). Bonus Points (Good to Have) • Experience with SIP Trunking (Twilio / Plivo / Exotel). • Knowledge of Vector Databases (Pinecone / Qdrant) for RAG. • Experience fine-tuning small models (Llama-3, Mistral) for specific tasks. • Familiarity with Docker & Kubernetes for deployment. 💡 How to Apply Send your resume + A GitHub link to a project where you used WebSockets or LLMs. (Resumes without code samples will be prioritized last). • For direct apply send your resume at singh.jyoti@cognitensor.com / +91 8262004185.

Requirements

• Python
• WebSockets
• asyncio
• ASR
• TTS

Preferred Technologies

• Python
• WebSockets
• asyncio
• ASR
• TTS