VoIP Engineer / FreeSWITCH Developer (C/Python) to $4000 Offline

About Us

Happ.AI is building AI-powered assistants for business. One of our key directions is voice assistants — intelligent systems that answer calls, solve typical client issues, escalate to humans when needed, and sync with CRMs.

We’re building a highly available telephony layer using FreeSWITCH, integrated with OpenAI GPT models and real-time voice analytics.

Who We’re Looking For

We’re searching for a VoIP engineer who:

• Has deep expertise in FreeSWITCH and is comfortable writing C modules
• Understands how to build and scale SIP-based voice infrastructures
• Has working knowledge of Python (for APIs, integrations, tooling)
• Enjoys working with open-source systems and solving practical engineering problems

• Can lead the VoIP direction technically and architecturally

   

Responsibilities

• Develop and optimize our FreeSWITCH-based call infrastructure
• Build and maintain high-load, low-latency VoIP systems (SIP, RTP, NAT traversal, etc.)
• Write custom FreeSWITCH modules in C
• Collaborate closely with backend and AI teams (FastAPI, GPT, Whisper, PostgreSQL)

• Automate deployment and call monitoring (e.g., HOMER, RTPengine)

   

Tech Stack

• FreeSWITCH, SIP, RTP/SRTP, WebRTC
• Python, FastAPI, PostgreSQL
• Docker, Kubernetes, Ansible

• GPT, Whisper, Voice Cloning

   

We Offer

• A chance to shape a cutting-edge AI voice product from the ground up
• Direct impact on tech decisions and product architecture
• Collaboration with a fast-moving founding team (no bureaucracy)
• Flexible hours and fully remote

• Competitive salary + performance-based bonuses

   

How to Apply

If you love working on real-time voice systems, open-source tech, and want to build something meaningful — let’s talk.