Senior Python Engineer (AI Voice Platform)

We are looking for a Senior Python Engineer to join a real-time AI voice/chat platform project. The product combines conversational AI, live audio streaming, speech recognition, text-to-speech, telephony, SIP/FreeSWITCH integrations, and external tool/action execution for AI agents.

The engineer will work on new product features, refactoring and performance optimization of the existing Python backend, and improvements in real-time voice call processing.

Responsibilities

• Build and improve real-time AI voice interactions over WebSocket, SIP, Twilio, and FreeSWITCH-based infrastructure.
• Work with streaming audio pipelines: STT, TTS, VAD, audio normalization, encoding/decoding, buffering, and low-latency processing.
• Integrate and optimize AI providers and SDKs such as OpenAI, Gemini, Anthropic, Deepgram, ElevenLabs, Azure Speech, and related APIs.
• Improve Python async and threaded components, including asyncio, background workers, queues, WebSocket handlers, and CPU/GPU-bound audio processing.
• Refactor existing backend modules to improve reliability, readability, testability, and performance.
• Design and implement new AI agent features: tool calling, knowledge retrieval, action execution, call routing, DTMF handling, and conversation workflows.
• Work with SIP/FreeSWITCH call flows, outbound/inbound calls, call transfers, hangups, status tracking, and media streaming.
• Debug production issues related to latency, concurrency, audio quality, memory usage, external API failures, and call state management.
• Collaborate on architecture decisions for scalable AI voice infrastructure.

Required Experience

• Strong senior-level Python experience in production backend systems.
• Deep knowledge of asyncio, multithreading, queues, task orchestration, cancellation, timeouts, and concurrency debugging.
• Hands-on experience with real-time audio processing, streaming audio, PCM/?-law, sample rates, audio chunks, silence detection, and latency-sensitive systems.
• Experience with AI/LLM SDKs and APIs, including streaming responses, function/tool calling, structured outputs, retries, pricing/usage tracking, and provider abstraction.
• Practical experience with STT/TTS/VAD technologies such as Deepgram, Whisper, Azure Speech, ElevenLabs, Silero VAD, or similar.
• Experience with FastAPI, WebSockets, Redis, MySQL, S3-compatible storage, and background processing.
• Ability to read, refactor, and stabilize an existing complex codebase without over-engineering.
• Strong debugging skills across async code, network services, external APIs, and audio pipelines.

Strong Plus

• Experience with SIP, FreeSWITCH, RTP/media streaming, SIP gateways, or telecom call routing.
• Experience with Twilio Voice Media Streams or similar programmable voice platforms.
• Experience optimizing ML/audio workloads with PyTorch, ONNX Runtime, CUDA, or GPU-aware processing.
• Experience with RAG/knowledge systems, Qdrant/vector search, BM25, and hybrid retrieval.
• Experience designing reliable AI agent systems with tool execution, external integrations, and stateful conversations.
• DevOps experience with Docker, Gunicorn/Uvicorn, observability, and production incident debugging.

Ideal CandidateThe ideal candidate is not just a Python backend developer, but someone comfortable at the intersection of AI, audio engineering, telecom, and high-concurrency backend systems. They should be able to ship new features, improve architecture, reduce latency, debug difficult production issues, and bring senior engineering judgment to a rapidly evolving AI voice product.