Principal AI Engineer - Personalization and Recommendation (Remote)

We believe that mental health is just as important as physical health. We recognize that mental health issues can be complex and multifaceted, and we are dedicated to treating the whole person, not just the symptoms. We aim to create a world where mental health is no longer stigmatized or marginalized, but rather is embraced as an integral part of one's overall well-being. We believe that by providing quality care that is both evidence-based and compassionate, we can empower individuals to take charge of their mental health and achieve their full potential. We are passionate about making a positive impact on the lives of those struggling with mental health issues and we strive to be a force for positive change in the field of mental healthcare. Rula is a remote-first company. We currently hire in most U.S. states, with the exception of Hawaii. About the Role At Rula, this role owns the applied AI and ML solutions that determine what, how, and how well AI shows up across mental healthcare. The focus isn't on isolated prototypes, but on building production-grade AI systems that directly power patient-provider matching, clinical workflows, and patient engagement. While your immediate focus will be driving search ranking, relevance, and patient-provider matching, your broader scope encompasses our overarching personalization and recommendation strategies, alongside directing the foundational ML platforms that support them at scale. You'll operate where applied research, system architecture, and real-world clinical constraints meet. The work spans developing advanced recommendation engines and retrieval models, applying NLP and generative AI to clinical workflows, setting technical standards for AI safety, and making principal decisions about how machine learning is introduced into a high-stakes environment. The goal is simple but hard: leverage applied AI-from intelligent matching and deep personalization to broader AI solutions-to make care more accessible and effective without compromising trust or outcomes. This is a deeply hands-on role with real technical ownership. You'll develop and fine-tune models (e.g., Learning-to-Rank, embeddings, recommendation algorithms, and LLMs), design both product-facing AI architectures and core ML infrastructure, unblock complex engineering problems, and act as a technical multiplier for engineers working across product surfaces. Success here means shipping applied AI features that tangibly improve match quality and the user experience, while simultaneously building scalable, durable AI foundations that others can build on confidently. The opportunity is less about chasing the AI frontier for its own sake and more about shaping how applied ML responsibly becomes part of everyday mental healthcare. You will set the direction not just for our immediate relevance and recommendation systems, but for how the entire AI ecosystem-from infrastructure to advanced clinical applications-evolves to actively improve patient outcomes over time. Required Qualifications • 10+ years of software engineering, including 7+ years of experience designing and scaling distributed systems, and 5+ years building and deploying production-grade ML applications. • 5+ years of deep, hands-on experience building and optimizing search, ranking, relevance, or recommendation engines at scale (e.g., Learning-to-Rank, collaborative filtering, deep recommender systems, semantic vector search) • 5+ years of strong programming experience in Python and at least one backend language (preferably TypeScript, Java, or Go), combined with 2+ years of experience building AI-powered products using foundation models (OpenAI, Anthropic, Gemini) and LLM integration patterns (RAG, agents, etc.) • Strong proven track record working with both traditional search/retrieval infrastructure (e.g., Elasticsearch, OpenSearch) and modern vector databases (e.g., Pinecone, Weaviate, FAISS, Milvus) • 3+ years of experience with MLOps, data pipelines, and rigorous evaluation systems (offline metrics like NDCG/MAP, online A/B testing), with a demonstrated ability to define technical strategy and guide the broader AI/ML infrastructure ecosystem Preferred Qualifications While having the preferred qualifications enhances your candidacy, having all of them is not mandatory. We encourage all interested applicants to apply, even those who may not meet every preferred requirement. • Experience architecting secure and compliant AI solutions in regulated environments (HIPAA, GDPR, etc.). • Familiarity with human-in-the-loop systems and clinical decision support frameworks. • Experience designing evaluation pipelines for human alignment, factual accuracy, or model interpretability. • Contributions to open-source AI frameworks or applied research in NLP, healthcare AI, or GenAI safety. • Experience contributing to early-stage team growth (0 → 1) • Experience leading or mentoring engineering teams in AI, ML platform, or applied research domains We're serious about your well-being! As part of our team, full-time employees receive: • 100% remote work environment: Working hours to support a healthy work-life balance, ensuring you can meet both professional and personal commitments (must be based in United States, currently not hiring in Hawaii) • Attractive pay and benefits: Full transparency of pay ranges regardless of where you live in the United States • Comprehensive health benefits: Medical, dental, vision, life, disability, and FSA/HSA • 401(k) plan access: Start saving for your future • Generous time-off policies: Including 2 company-wide shutdown weeks each year for self-care (for most employees) • Paid parental leave: Available for all parents, including birthing, non-birthing, adopting, and fostering • Employee Assistance Program (EAP): Supporting your mental and physical health • Quarterly department stipend: Fun team-building activities or in-person gatherings • Community and employee resource groups: Participate in groups that celebrate employee identity and lived experiences, fostering a sense of community and belonging for all • Home office stipend: New hire home office stipend & $50 monthly stipend to help cover internet or cell phone expenses • Wellness at Rula program: Year-round wellness initiatives and a $50/month wellness stipend Our team We believe that diversity, equity, and inclusion are fundamental to our mission of making mental healthcare work for everyone. We are dedicated to having a culture of inclusion that will support our employees in feeling safe, seen, heard, and valued.