Senior Prompt Engineer

Senior Prompt Engineer

Location: Remote work is fine. Or availability to work from Sunnyvale or Los Angeles office.

Schedule: Full time, 40 hours per week.

Cairns Health is looking for a full-time Senior Prompt Engineer to craft, test, and refine prompts for Luna, our AI-powered digital health companion. This role is ideal for someone who can write  prompts in a way that helps us successfully achieve results we’re looking for from our model. Someone with technical skills, who’s very familiar with the tooling to automate testing. The ideal candidate has built an LLM-based application with a prompt that serviced millions of people. While also has an attention to nuance, tone, and clarity in conversational UX.

In this role, you’ll blend creativity and precision to design prompts that deliver empathetic, clinically appropriate, and technically reliable responses. You’ll work closely with product, engineering, and clinical teams to develop and iterate on prompts that drive real-world impact for patients managing chronic conditions.

What You’ll Do

• Write, refine, and maintain prompts based on product specs, user personas, and clinical scenarios.
• Use tools like OpenAI API, AWS Bedrock, and internal test frameworks to evaluate prompt performance.
• Rapidly iterate on prompts based on output analysis, user interaction data, and team feedback.
• Collaborate with product managers, engineers, and clinical advisors to align tone, behavior, and therapeutic goals.
• Conduct structured testing, including A/B tests, hallucination checks, and performance scoring.
• Contribute to internal prompt libraries, version control, and documentation best practices.
• Help define and improve our prompt development methodology and safety checks.

What We’re Looking For:

• Demonstrated success crafting high-quality prompts for LLMs, ideally with OpenAI’s API.
• Strong grasp of prompt engineering workflows, prompt chaining, and prompt evaluation techniques.
• Familiarity with prompt testing tools such as OpenAI Playground, AWS Bedrock, or LangChain.
• Analytical mindset with experience using structured testing, evaluation metrics, or model output analysis.
• Excellent writing skills and attention to nuance, tone, and clarity in conversational UX.
• Curious and iterative thinker who sees prompt engineering as both creative exploration and systematic tuning.
• Interest in healthcare technology and enthusiasm for improving patient outcomes through AI.
• Comfortable working independently in a fast-moving, low-structure startup environment.

What We Offer:

• Full time work with a competitive salary.
• Benefits: we offer a comprehensive benefits package, including medical, dental, vision, paid time off, and a 401(k) plan.
• Opportunity to shape the behavior and voice of Luna, our state-of-the-art AI companion for older adults.
• Collaborative team with deep experience in AI, healthcare, and product design.
• Meaningful work that supports real patients and caregivers.

About Us:

Cairns Health builds conversational AI tools to support people with chronic conditions and the people who care for them. Our digital care companion, Luna, provides medication reminders, symptom checks, behavioral nudges, and companionship — all powered by cutting-edge AI and context-aware sensing technologies. By simplifying care plans and enabling proactive intervention, we improve clinical outcomes, reduce care costs, and make healthcare more human. Learn more here: www.cairns.ai.

To Apply:

Please apply here. Then send your resume and cover letter to nicky @cairns. ai