Senior AI Engineer

About Prosper AI Prosper is building the most advanced conversational AI agents for healthcare — human-like phone agents that handle the administrative work draining the system: claims status checks, benefit verification, prior authorizations, patient scheduling, and balance reminders. Our mission is to eliminate $200B in administrative waste so healthcare professionals can focus more on healing and less on paperwork. Headquartered in New York with an office in Barcelona, we work with dozens of large and enterprise healthcare organizations, and we've raised $35M from top investors including a16z, Base10, YC, and Emergence. We're a highly motivated team of 40 — ex-MIT, HBS, Bain, and Math/CS/Physics olympiad medalists — and as we prepare for our next stage of growth, we're looking for ambitious, exceptionally talented people to help scale our product and grow with us. What you'll do 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). Interviewing Process 1. Initial conversation to understand who you are, what you want to do, and where you wanna go (30 minutes) 2. Work on a take-home challenge to discuss in the following interview 3. Review your solution with a couple of engineers from the team (60 minutes) 4. Talk with the co-founder (60 minutes) 5. Offer stage