Senior AI Engineer (Full Remote in Spain or UK) with experience in Real-Time Voice & Text Systems

Our client is a

pioneering HealthTech scale-up

developing a first-of-its-kind AI assistant designed by clinicians, for clinicians. They are tackling one of the most urgent global challenges: the critical shortage of healthcare professionals. By building a controllable and highly customizable 'AI brain,' they provide real-time, reliable support across the entire care continuum. This is a chance to work on a product where your code directly alleviates the burden on frontline medical staff.

As

AI Engineer , you will own and evolve the core "brain" service of this company platform. This is not about building simple wrappers; you will architect sophisticated multi-agent systems that reason and communicate in real-time via voice and text. You will tackle high-stakes challenges in low-latency streaming, autonomous orchestration, and continuous evaluation, shipping fast-moving Python services at the intersection of cutting-edge AI and human-centric health technology.

We can hire this position ideally in Spain or UK.

Main Responsibilities:

Core Intelligence Ownership:

Lead the end-to-end architecture and evolution of the "core brain" service, taking full responsibility for SLAs, latency budgets, and deployment strategies. Real-Time Voice & Text Systems:

Design and operate low-latency communication systems featuring streaming voice/text, Voice Activity Detection (VAD), and complex interaction handling (barge-in, turn-taking, and interruptions). Advanced Multi-Agent Orchestration:

Build sophisticated multi-agent systems using planner–executor–critic patterns, shared memory, and advanced coordination protocols. Reasoning Optimization:

Implement and refine complex reasoning frameworks, including ReAct and Chain-of-Thought (CoT), as well as Tree/Graph-of-Thought architectures where applicable. Automated Prompt Engineering:

Leverage programmatic optimization tools (such as DSPy, MiPRO, or GEPA) to compile and evolve prompts iteratively under strict evaluation constraints. High-Performance RAG Engineering:

Develop robust Retrieval-Augmented Generation (RAG) pipelines focusing on high-signal retrieval, hybrid search, re-ranking, and query rewriting to ensure grounded and faithful AI responses. Observability & Continuous Evaluation:

Architect a comprehensive evaluation framework—from pre-call safety checks to post-call automated evals (hallucination detection, red-teaming)—using OpenTelemetry and structured logging to monitor drift and performance in real-time. High-Velocity Backend Development:

Ship high-quality, production-ready Python services using FastAPI, ensuring high performance and continuous integration/deployment (CI/CD) gates.

Requirements:

Core Backend:

Extensive experience with

Python ,

FastAPI ,

Pydantic , and

asyncio

for high-performance service development. AI & Data:

Proven track record with

Multi-agent systems ,

Vector Stores , and advanced RAG architectures. Infrastructure:

Proficiency in

Docker ,

Kubernetes (K8s) , and

Terraform

for scalable deployments. Real-Time Ops:

Familiarity with

STT/TTS

(Speech-to-Text/Text-to-Speech) and monitoring via

OpenTelemetry (OTEL) .

Preferred Experience (Nice to Have)

Real-Time Communication:

Hands-on experience with

WebRTC stacks ,

LiveKit , and

SIP gateways . AI Evaluation:

Deep dive into

DeepEval

or similar LLM-as-a-judge frameworks. Prompt Optimization:

Experience using

DSPy

for automated prompt compilation and self-improving workflows.

What's on offer?

Stability & Growth:

Permanent contract

with a long-term vision and deep investment in your professional journey. Impactful Work:

Build cutting-edge, real-time agent technology within a best-in-class HealthTech team where your code has a direct impact on global healthcare. High-Octane Technical Environment:

Join a highly motivating atmosphere that fosters continuous learning, peer-to-peer mentorship, and the freedom to experiment with the latest AI breakthroughs. Flexibility & Balance:

Truly flexible work-life integration with

Remote-first or Hybrid

options in our

Barcelona

hub. For people living in another Spanish cities the position can be remote. Team Culture:

Engaging team-building events and

fun off-sites in Barcelona

to connect with a diverse, international team. Premium Tools:

High-tech laptop of your choice and a budget for

solid dev ergonomics

to ensure your workspace is optimized for peak performance. Continuous Learning:

Access to the latest tools, research papers, and internal knowledge-sharing sessions on the frontier of Multi-agent systems and LLMs.

Our recruitment process?

Step 1: Interview with one of our recruiters Step 2: Technical Interview with Hiring Manager Step 3: Interview with another member of the team Step 4: Cultural Fit Interview