Lead ML Research Engineer (Portugal-based Remote/Hybrid)

Sword Health is on a mission to free two billion people from pain. 
With 67% of members achieving a pain-free life and a 70% reduction in surgery intent, at Sword, we are using AI Care to change lives, and save millions for our 25,000+ enterprise clients across three continents. Today, we hold the majority of industry patents, win 70% of competitive evaluations, and have raised more than $300 million from top venture firms like Founders Fund, Sapphire Ventures, General Catalyst, and Khosla Ventures.
Recognized as a Forbes Best Startup Employer in 2025, this award highlights our focus on being a destination for the best and brightest  talent. Not only have we experienced unprecedented growth since our market debut in 2020,  but we’ve also created a remarkable mission and value-driven environment that is loved by our growing team. With a recent valuation of $3 billion, we are in a phase of hyper growth and expansion, and we’re looking for individuals with passion, commitment, and energy to help us scale our global impact. 
Joining Sword means committing to a set of core values, chief amongst them to “do it for the patients” every day, and to always “deliver more than expected” on behalf of our members and clients.
This is an opportunity for you to make a significant difference on a massive scale as you work alongside 900+ (and growing!) talented colleagues, spanning three continents. Your charge? To help us build a pain-free world, powered by AI, enhanced by people — accessible to all.

What you’ll be doing:

• Guide ML Engineers and ML Research Engineers through technically complex projects such as LLM continued pre-training, architectural innovations, or adapting and training open-source models (TTS, STT, etc.);
• Identify and define new research directions that align with Sword’s strategic goals;
• Serve as the technical anchor for the AI team, providing expertise on cutting-edge approaches and implementation strategies;
• Author and publish technical papers and blog posts to document research findings;
• Stay at the forefront of GenAI advancements and proactively bring this knowledge to the team through regular knowledge sharing sessions;
• Bridge the gap between research innovations and practical implementations by collaborating with Product, Data & Engineering teams;
• Mentor team members to grow their technical and research capabilities.

What you need to have:

• PhD in Computer Science, Machine Learning, or related field;
• 5+ years of experience in AI/ML in industry with demonstrable technical contributions;
• Publication record or demonstrable research output in machine learning or AI;
• Deep technical expertise in GenAI (LLMs, generative models, speech, etc.);
• Experience leading technical teams through complex research challenges in fast-paced, product-focused environments;
• Proven ability to translate research concepts into practical implementations;
• Good coding skills in Python and familiarity with modern ML frameworks (PyTorch, TensorFlow, etc.);
• Experience with the full ML lifecycle, from ideation to deployment;
• Strong communication skills with the ability to explain complex technical concepts to diverse audiences;
• Strong product sense and impeccable ability to do research with strong alignment towards business objectives.

What we would love to see:

• Contributions to open-source AI/ML projects;
• Experience applying research in healthcare or related domains;
• Familiarity with MLOps and experiment tracking tools;
• Experience establishing research collaborations with academic institutions;
• Passion for healthcare technology and its potential to improve lives.

To ensure you feel good solving a big Human problem, we offer:

• A stimulating, fast-paced environment with lots of room for creativity and ownership;
• Career development and growth, with a competitive salary;
• The opportunity to work with a talented team on cutting-edge AI/ML applications that have the potential to transform the future of healthcare;
• A flexible environment where you can control your hours (remotely) with unlimited vacation;
• Access to our health and well-being program (digital therapist sessions);
• Remote or Hybrid work policy.

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• English class

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, which includes SWORD Health, Inc. and Sword Health Professionals (consisting of Sword Health Care Providers, P.A., SWORD Health Care Providers of NJ, P.C., SWORD Health Care Physical Therapy Providers of CA, P.C.*) 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.