Sr. Full-Stack Engineer, Applied AI

Hims & Hers is the leading health and wellness platform, on a mission to help the world feel great through the power of better health. We are redefining healthcare by putting the customer first and delivering access to care that is affordable, accessible, and personal, from diagnosis to treatment to delivery. No two people are the same, so we provide access to personalized care designed for results.

By normalizing health & wellness challenges and innovating on their solutions, we’re making better health outcomes easier to achieve.

We’re looking for a Sr. Full-Stack Engineer to join the Applied AI team to build the core infrastructure that powers our next generation of AI-powered health experiences.

Our Applied AI organization is building the foundation for all AI-powered products and experiences at Hims & Hers. This team is responsible for the models, platforms, tools, and systems that enable intelligent, safe, and scalable health automation — from conversational agents and care coaching to logistics and fulfillment.

The ideal candidate is curious, action-oriented, and deeply technical — someone who loves learning, experiments fast, and iterates toward high-quality outcomes. You’re a fast learner who thrives at the intersection of AI, systems, and product engineering. You care about building technology that improves patient care, makes providers more effective, and simplifies complex health operations. You’ll work across Type Script and Python, collaborating with AI researchers, product managers, and data scientists to bring powerful, safe AI features to life.

• Design and build scalable AI workflow systems — including orchestration runtimes, SDKs, and observability pipelines that power real-time, intelligent experiences.
• Develop end-to-end features using Type Script (Cloudflare Workers, React/Next.js) and Python (Databricks, evaluation, data processing).
• Integrate and evaluate large language models (LLMs) and other ML systems (OpenAI, Anthropic, Vertex, Databricks) via a unified AI Gateway.
• Build tool connectors and APIs for our internal domains — EHR, Pharmacy, Payments, Orders, Care — enabling safe and automated cross-system workflows.
• Develop evaluation and feedback systems that measure quality, grounding, latency, and safety of AI-powered flows.
• Partner closely with AI, Product, and Infra teams to design, prototype, and iterate quickly — turning research into production capabilities.
• Contribute to shared Type Script and Python SDKs that standardize event schemas, tool contracts, and developer experience across Applied AI.
• Ensure everything you build meets security-by-design and privacy-first principles, supporting HIPAA and compliance requirements.
• Foster a build → measure → learn culture by testing fast, gathering feedback, and continuously improving the system.

• 4+ years of professional full-stack experience, spanning backend APIs, frontend apps, infra, and data systems.
• Proficient in Type Script (Node.js, React) and Python (data pipelines, ML evaluation, orchestration).
• Familiarity with LLM- or ML-based systems, including prompt orchestration, evaluation harnesses, or RAG pipelines.
• Experience with workflow orchestration tools.
• Understanding of system design for AI workloads — including state management, retries, idempotency, and performance optimization.
• Experience with data/ML infrastructure (Databricks, AWS, vector stores, or Big Query).
• A bias toward action and iteration — you build fast, validate ideas early, and improve based on results.
• Collaborative mindset, with strong communication skills.
• Awareness of AI lifecycle management — from experimentation and evaluation to safety and deployment.

• Building AI evaluation or observability systems, such as LLM-as-a-judge frameworks or human review pipelines.
• Experience with Databricks, Cloudflare Durable Objects, or other edge orchestration systems.
• Background in healthcare, life sciences, or regulated industries.
• Contributions to open-source SDKs or AI infrastructure projects.
• Experience creating visual workflow editors or n8n-style automation tools.

• Competitive…