Full Stack AI Engineer (Lisbon)

The opportunity

Menhir is looking for a generalist full stack engineer to join our Lisbon headquarters and work on one of our venture development products: an AI-powered revenue recovery platform for healthcare clinics across Europe and the Americas. We believe the best person for this role is someone who can move across the entire stack, from infrastructure to product to AI, rather than a specialist in any single layer.

Our voice and WhatsApp AI agents recover lost patients for clinic groups, operating 24/7 with deep integration into clinic management systems. We already work with some of the largest healthcare groups in Europe, spanning hundreds of clinics across dental, veterinary, ophthalmology, and aesthetic medicine. Patient recovery is the wedge. We are building toward the payments and financing layer for healthcare.

The role

You will be the first engineer based in Lisbon, working directly with the Menhir team that created the product. This is a generalist role by design: you will work across the full stack, from AI agent orchestration to the product interfaces our clinic partners and their patients use every day.

You will not be handed tickets. You will shape the product alongside the team, making decisions that define how it scales from hundreds of clinics to tens of thousands across multiple markets.

What you will work on: AI agent systems (orchestration, conversation flows, evaluation pipelines, prompt engineering, telephony and messaging APIs), product and dashboard (data visualizations, campaign management), new product development (patient-facing experiences, financial infrastructure), and integrations with clinic management systems across markets.

What we are looking for

You build things. You have side projects, open source contributions, or products you shipped on your own. We care about what you have built, not where you studied.

You learn fast. You do not wait for documentation or a senior engineer to unblock you. You dig in and make it work.

You are a generalist. You can build a frontend, design an API, write a database query, and debug a deployment. At this stage, we need someone who can own problems end to end.

You have worked with LLMs. Hands-on experience building with language models, not just running prompts in a playground.

Python and TypeScript. Our core languages. You should be productive in both, or confident you can get there quickly.

You want ownership, not tickets. Ambiguity excites you, not paralyzes you.

0 to 3 years of experience. Or more, if you still have the hunger.

Bonus points for experience with real-time voice systems, Twilio, or WhatsApp Business API.

English is a must. Spanish or Portuguese are nice to haves.

Competitive salary. Lisbon-based, working from Menhir's headquarters. You will collaborate with the team that built the product (Madrid and international) and be the technical anchor on-site.

How to apply

Send us a short note about what excites you about this role and a link to something you have built. We care far more about what you have shipped than where you went to school.