Senior Backend Engineer – FastAPI, SIP/VoIP, Real-Time AI System

We are building an AI-powered CRM and technician tracking platform specifically designed for a field service business, with a long-term goal of turning it into a SaaS product.

The system will handle:

• Real-time AI call handling (via Telnyx SIP + Deepgram transcription + Dialogflow CX)
• Live job management & technician assignment
• Technician GPS tracking (Google Maps API integration)
• Real-time CRM dashboard

What You'll Work On:

• Backend architecture & development using FastAPI (Python) & Uvicorn
• SIP/VoIP integration with Telnyx API
• Real-time transcription pipeline using Deepgram (or similar)
• Connecting transcription to Dialogflow CX agent for AI call handling
• Implementing real-time WebSockets & webhook systems for job/technician status updates
• Database schema design (PostgreSQL or MongoDB) for customer, job, technician records
• Integration with Google Maps API for live technician GPS tracking
• Ensuring low-latency, highly reliable performance for voice & data streams
• Preparing for eventual scaling to SaaS (multi-tenant architecture considerations)

What We’ve Already Done:

• Basic FastAPI backend set up
• Telnyx SIP configuration & initial webhook handling
• Preliminary Dialogflow CX planning

You won’t be starting from scratch—you’ll be coming in to optimize, clean, and finish.

Key Requirements:

• 5+ years backend development experience
• Strong Python skills, particularly FastAPI & async programming
• Proven experience integrating SIP/VoIP systems (Telnyx, Twilio, etc.)
• Experience with real-time systems: WebSockets, webhooks, background tasks
• Solid understanding of database design (PostgreSQL or MongoDB)
• Familiarity with Google Maps API integration
• Comfortable optimizing for low-latency, high-volume systems

Bonus Skills (Nice-to-Have but NOT Mandatory):

• Experience working with speech recognition APIs (Deepgram, Whisper, Google STT)
• Knowledge of Dialogflow CX or similar NLP platforms
• Background in CRM or dispatch systems
• Experience scaling platforms for SaaS

Project Details:

• Freelance, project-based (fixed price or hourly negotiable)
• Open to part-time or full-time commitment for the right candidate
• Immediate start preferred—looking to move fast
• Budget: Competitive, but realistic (we’re not paying bloated agency rates)