Senior Full Stack / Backend Engineer

VoiceB | Fully Remote (Spain) | Engineering

What you'll do

• Design and build core systems behind our autonomous voice agent platform — real-time voice pipelines, LLM orchestration, telephony integrations and CRM connectors.
• Own the voice infrastructure layer: Twilio, SIP trunks, WebRTC, and the real-time audio plumbing that makes a sub-second AI conversation feel human.
• Ship full stack when needed — backend is your home, but you're comfortable touching the frontend to deliver end-to-end.
• Work directly with our CTO and a small, senior engineering team where every line of code matters.
• Integrate with Salesforce, HubSpot, ad platforms (Google, Meta) and enterprise CRMs.
• Contribute to architecture decisions that will define how voice AI scales over the next 5 years.

What we're looking for

• 5+ years building production backend systems (Node.js, Python, Go, or similar).
• Han...