AI Research Scientist (Multimodal post-training)

Posted:
4/14/2026, 6:46:29 AM

Location(s):
Lisbon, Portugal ⋅ Greater London, England, United Kingdom ⋅ Normandy, France ⋅ England, United Kingdom

Experience Level(s):
Mid Level ⋅ Senior

Field(s):
AI & Machine Learning

Workplace Type:
Hybrid

At Sword, we’re building AI to heal billions and unlock humanity’s full potential. In doing so, we’re pioneering AI Care, a fundamentally new approach to healthcare built for medical reasoning, safety, and real-time treatment, not generic technology applied after the fact. As both a clinical-centric frontier AI lab and an applied AI platform, Sword is reimagining how care is delivered at scale, removing traditional barriers like appointments, waiting rooms, and stigma so more people can access the care they need—and ultimately get back to lives lived in full.

Since 2020, Sword has expanded across physical therapy, women’s health, cardiometabolic, and mental health, and is now moving beyond the session to a fully AI-native, 24/7 care program that brings physical activity, therapeutic exercise, psychotherapy, nutrition, and behavior change into one connected experience. More than 700,000 members across three continents have completed over 10 million AI sessions, helping 1,000+ enterprise clients avoid more than $1 billion in unnecessary healthcare costs. Backed by 42 clinical studies, 44+ patents, and more than $500 million raised from leading investors including Khosla Ventures, General Catalyst, and Founders Fund, Sword is defining a new standard for healthcare.

At Sword, we operate as both a clinical-centric frontier AI lab and an applied AI platform — conducting the foundational research that makes clinical AI possible, then putting it into practice through platforms that treat patients directly. Our AI Research team builds the core intelligence behind Dawn and Phoenix, our continuous, always-on care agent.

Healthcare demands AI that goes far beyond answering questions or completing tasks. It requires systems capable of sustained engagement across dozens of interactions — understanding a patient's history, perceiving their present state, and guiding their recovery over weeks and months. Delivering care at this level means AI must see, hear, and understand patients across modalities. To make this possible, we are pushing the boundaries of multimodal perception — fusing video, language, and speech into unified patient understanding — alongside memory systems and multi-turn reinforcement learning for long-horizon treatment planning.

We are building a category of AI product that has never existed before — AI that provides real clinical care autonomously, at scale. That means operating at the frontier of both research and product development simultaneously, often without a playbook. You will thrive here if you are energized by uncertainty, comfortable making high-stakes decisions with incomplete information, and motivated by the outsized impact that comes with pioneering something genuinely new. It's high pressure, high reward — and the team that does it best.

Our researchers don't choose between scientific rigor and product impact. The team actively publishes in top-tier AI conferences and clinical journals while shipping the models that power care for hundreds of thousands of patients. We have the computer, the data, and the team to support your best work.

Location: We welcome applications from candidates across Europe and the UK. We have a preference for candidates based in London, UK, or Lisbon / Porto, Portugal, where our research team is primarily located and where we have active offices, but exceptional candidates elsewhere in Europe will absolutely be considered.


*This range includes base, variable and equity

These compensation bands are just the starting point. Once someone joins and proves they’re outlier talent, we adjust quickly to ensure their compensation aligns with their impact.

Our job titles may span more than one career level. Actual pay is determined by skills, qualifications, experience, location, market demand, and other factors. Compensation details listed in this posting reflect the base salary and any potential variable, bonus or sales incentives, and the Company’s estimation of the value of private company stock options, if applicable. The pay range is subject to change, future value of company stock options is not guaranteed, and compensation may be modified in the future. In addition to our total compensation, Sword offers a number of benefits as listed below.
 
Portugal - Sword Benefits & Perks:
 
• Health, dental and vision insurance
• Meal allowance
• Equity shares
• Remote work allowance
• Flexible working hours
• Work from home
• Discretionary vacation
• Snacks and beverages
 
Note: Please note that this position does not offer relocation assistance. Candidates must possess a valid EU visa and be based in Portugal.
 
Sword Health complies with applicable Federal and State civil rights laws and does not discriminate on the basis of Age, Ancestry, Color, Citizenship, Gender, Gender expression, Gender identity, Gender information, Marital status, Medical condition, National origin, Physical or mental disability, Pregnancy, Race, Religion, Caste, Sexual orientation, and Veteran status.