Senior AI Engineer

At Prosper, we’re pushing the limits of what’s possible with real-time AI. We’re not just making voice agents that “talk”, we’re engineering systems that sound human, reason under strong latency constraints, and adapt instantly to messy, high-stakes healthcare conversations. As a Software Engineer, you’ll be at the center of designing and scaling our platform, the low-latency speech/LLM pipelines, orchestration layers, and reliability systems that make this possible.

This is a full-time role in Barcelona office with the possibility to move to the New York office.

What we're looking for

• 3-5 years of experience building products end-to-end, from architecting solutions to deploying production-grade software.

• A strong understanding of the technologies that power our stack or their equivalents in other languages: FastAPI (Python) + PostgreSQL backend with a React (TypeScript) frontend.

• Experience managing large scale distributed systems with asynchronous workload orchestration.

• Familiarity with LLMs, AI agents or other ML models is a plus. We use Pipecat for our voice agents.

• Founder mindset: ownership + hard work. You see Prosper as a learning step for your future startup.

• Be ready to handle the challenges of deploying AI voice agents to thousands of daily phone calls.

• Bachelor’s or Master’s degree in Computer Science, Engineering, Maths, Physics or related field (or equivalent experience).