Staff Research ML Engineer (Europe-based/Remote) at Sword Health

Sword Health's Applied AI Team develops AI and ML solutions that power personalized clinical care at scale, including end-to-end AI treatment management systems that handle complete care pathways. They are building Phoenix, an AI Care Specialist that engages in ongoing dialogue with patients and provides clinical guidance throughout their recovery journey. Posted: November 21, 2025 (still active) Type: Full-time, Hybrid Location: Europe-based, Remote As Staff Research ML Engineer, you will own complex ML problems end-to-end, from exploration through production deployment. The work spans the full AI stack: prompt engineering, RAG implementations, model fine-tuning, and agentic workflows. The team leverages both generative AI and classical machine learning depending on what the problem requires. Key Responsibilities: - Manage complex ML challenges from exploration through production deployment - Design technical strategy for model development and optimization in clinical applications - Build and optimize production LLM systems, including fine-tuning pipelines and evaluation frameworks - Work across the complete AI stack from data preparation to monitoring - Influence technical decisions across teams - Mentor engineers and establish best practices - Potentially lead 1-2 engineers on specific projects Required Qualifications: - Proven experience building and shipping production ML systems - Production LLM fine-tuning and deployment expertise - Implementation experience with preference optimization techniques (RLHF, DPO) - Strong ML fundamentals and evaluation framework design - End-to-end ownership of complex problems from exploration through iteration - Production-quality coding and distributed systems knowledge - Cross-team communication and influence abilities Desired: - Healthcare AI or clinical applications experience - LLM evaluation framework design for specialized domains - Open source contributions or technical community involvement Benefits: - Competitive salary with career development - Unlimited vacation - Digital health/therapist access - Remote or hybrid work arrangements Interview Process: Five stages - recruiter call, technical screener, take-home assignment, skills/principles interview, cultural fit discussion. Sword Health has raised $500M+ from investors including Khosla Ventures and General Catalyst. Over 700,000 members completing 10 million AI sessions since 2020.