Mid Forward Deployed 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 integrate seamlessly with our customers' complex internal tools. As a Forward Deployed Engineer, you'll work side by side with our AI PMs to find technical opportunities that increase the performance of our agents for each of our clients.

Day to day, you'll

• Build features that ship fast — develop new capabilities, MVPs, and internal tooling across our FastAPI (Python) + PostgreSQL backend and React (TypeScript) frontend, with a bias toward getting things in front of clients quickly.

• Integrate with messy real-world systems — build and maintain integrations with EHRs and payor systems (and the APIs, edge cases, and quirks that come with them) so agents fit seamlessly into each client's stack.

• Debug live, high-volume systems — diagnose and resolve issues for agents making thousands of daily phone calls, where reliability and call quality directly affect patient and provider experience.

• Turn client feedback into product — close the loop with AI PMs and engineering, surfacing patterns across clients and feeding them back into the core platform.

• Tune and optimize voice agents — iterate on LLM prompting, voice and transcription configuration, and conversation logic to make agents sound more human and perform reliably under real-time latency constraints.

• Manage multiple clients at once — prioritize across competing deadlines while keeping quality high.

What we're looking for

• 3+ years experience with software development

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

• Experience working closely with clients and finding creative solutions to their needs.

• Familiarity with LLMs, AI agents or other ML models is a plus.

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

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

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

What We Offer

• The opportunity to work alongside an experienced team that has built and scaled a fast-growing, Series A company backed by top Silicon Valley investors

• Work on innovative products that are transforming US healthcare operations and sit at the heart of conversational agents.

• Significant growth opportunities as the company scales and the team takes on increasing ownership

• Competitive compensation

• Join an international team based in the heart of Barcelona

• Have real ownership and impact from day one

• Be part of a culture that rewards bold thinking, analytical rigor, and tangible results

• Flexible environment