Senior AI Engineer

Prosper AI; Barcelona; On-site; EUR 45,000 - 65,000; Full time

Job summary

A leading AI technology company located in Barcelona is seeking a Software Engineer to design and scale their AI platform. This full-time on-site role involves developing low-latency speech pipelines and ensuring the reliability of AI voice agents deployed to handle thousands of daily calls. Ideal candidates have a strong background in Python and JavaScript, along with experience in complex software solutions and a collaborative mindset. This presents a unique opportunity for growth and innovation in the AI space.

Qualifications

• 3-5 years of experience building complex software solutions.
• Solid grasp of algorithms, data structures, and software engineering best practices.
• Familiarity with LLMs, AI agents, or other ML models is a plus.

Responsibilities

• Design and scale platform, low-latency speech/LLM pipelines, and orchestration layers.
• Handle challenges of deploying AI voice agents to thousands of daily phone calls.

Skills

Python

JavaScript

React

Algorithms

Data Structures

Large Scale Distributed Systems

Education

Bachelor’s or Master’s degree in Computer Science, Engineering, Maths, Physics or related field

Job description

About Prosper AI

Prosper AI specializes in AI Phone Agents for healthcare, providing human-like expertise while significantly reducing costs. Our AI Agents efficiently handle tasks for calling patients and payors such as claims status checks, benefit verification, prior authorizations, patient scheduling, and balance reminders. We aim to eliminate $200B in administrative waste, allowing healthcare professionals to focus more on healing and less on administrative tasks.

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 on-site role located in Barcelona with the possibility to move to the New York Office.

What we're looking for

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

• 3-5 years of experience building complex software solutions.

• Solid grasp of algorithms, data structures, and software engineering best practices, especially in Python and Javascript/React.

• Experience managing large scale distributed systems with asynchronous tasks.

• 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 deploying AI voice agents to thousands of daily phone calls.

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