AI Research Engineer

The Path is a research lab and consumer health company on a mission to provide therapy-grade help and coaching for anyone, anytime.

Over 3 billion people a year have a problem large enough to warrant therapy but the barriers to access - around price, time, geography, stigma, and language - are so large that less than 10% of these people are getting the help they need.

The Path exists because help shouldn’t depend on privilege, because intelligence should serve humanity, and because clarity is the first act of care.

Our purpose-built AI therapists provide evidence-based mental health support delivered through artificial intelligence, designed to get smarter with every session. The Path was built by a neuroscientist who understands how the brain actually changes. Most AI chat tools were not.

Every role here moves that work forward. Join a small, passionate in-person team in San Francisco building the AI and the clinical research behind it!

Design, train, ship, iterate on, and innovate on the AI brains behind The Path’s AI Therapist. Combine research, data science, and engineering to create models, orchestration, and evaluation systems that make therapy conversations deeply effective, clinically grounded, and safe.

Note - Below contains the outcomes and competencies for the team. If you bring standout strengths in some areas but not all, you are still encouraged to apply.

• Improve quality of AI Therapy: Deliver measurable improvements in conversation quality, therapeutic alliance, and user outcomes through fine-tuning strategies, training data curation, building RL environments, new model architectures and other AI innovations.

• Improve evaluation of AI quality: Improve on and maintain a robust eval stack that includes scripted tests, LLM-as-judge evaluations, human ratings, and safety checks. Improve automated regression testing, detection of defects, and observability (eg dashboards).

• Own AI system. Build, maintain, and iterate on the production codebase that delivers AI therapy and supports the evaluation and iteration of our AI.

• Productionize Models and Pipelines. Own The Path from notebook to production: training jobs, model packaging, deployment, monitoring, and rollback strategies. Keep latency, reliability, and cost within agreed budgets while enabling rapid iteration on new ideas.

• Safety, Alignment, and Clinical Guardrails Work with clinicians and internal experts to encode clinical guidelines into prompts, reward functions, tools, and filters. Proactively identify and reduce harmful or low-quality behaviors through targeted experiments, red teaming, and mitigations.

• Own Research Roadmap and Experiment Velocity Run high-quality experiments from hypothesis to analysis to improve our understanding of what matters and what works. Shape and execute a focused R&D roadmap.

• Collaboration with Clinicians, Product, and Engineering. Translate product and clinical requirements into concrete model and system changes. Partner with full-stack product engineers so that new AI capabilities are easy to integrate and maintain in the product.

• LLM and Applied ML Depth. Demonstrates strong experience with large language models, including fine-tuning, training data design, and model selection. Knows how to move core metrics on conversation quality and user outcomes, rather than chasing generic benchmarks. Can look at evals, transcripts, and metrics and quickly form grounded hypotheses for improvement.

• Ships clean, maintainable, quality code. No only do you know how transformers work, but you are also an engineer that has experience shipping production-level code and/or maintaining an AI system in production.

• Data Engineering Skills. Can set up production-level data pipelines for training new models, evals, analysis, etc.

• Scientific Mindset. You formulate hypotheses, and you are good at evaluating them (eg through experiments, data analysis, etc). You are consistently learning at the cutting edge, and you’re able to leverage and communicate those learnings to make the entire company more successful.

• Ruthless Prioritizer. You are keenly aware of how to provide company value and to prioritize projects accordingly. Resistant to nerd-sniping.

• Quality Obsessive: Refuses to ship subpar work, continuously improving the codebase.

• Fast: Prioritizes speed by leveraging AI, breaking down complex tasks, shipping early, optimizing for learnings, iterating quickly, and avoiding over-engineering.

• Strong communicator. You can work collaboratively in a positive way. Sees others perspectives. Strong opinions, loosely held. Focused on user/business value, not ego.

• Personal or other experience with therapy or coaching

• Domain knowledge of psychology, neuroscience, therapy, or coaching.

• Work Model - San Francisco hybrid (Tue–Thur in office Union Square). Full-time

• Benefits - comprehensive health/dental/vision/life insurance , flexible PTO, and WFH reimbursement

• Our team thrives in a high-trust culture that fosters individuality, creativity, agency, and development

The Path is proud to be an equal opportunity employer. We celebrate diversity and encourage applications from everyone; especially those whose identities are traditionally underrepresented in tech. We do not discriminate on race, religion, color, gender expression or identity, sexual orientation, ancestry, national origin, citizenship, age, marital status, veteran status, disability status, political belief, or any other characteristic protected by law.

We’re excited to review your application! If your experience aligns with business needs, our hiring team will reach out to schedule an initial screening call and walk you through the next steps of our interview process.

While we try our best to respond to everyone, the high volume of applications may mean we’re unable to provide individual updates if we decide not to move forward.