Senior Full Stack Engineer (f/m/d)

ABOUT US: Kyan Health is an AI-powered enterprise solution that connects employee well-being with measurable business impact. Using predictive analytics, Kyan helps companies monitor and reduce risks like absenteeism, turnover, and presenteeism. We believe in harmonizing work and life, fostering a positive environment that champions performance and personal growth and well-being at the same time. Our culture thrives on innovation, collaboration, and the well-being of every team member. SOME THINGS WE’RE PROUD OF - 🧠 Building an industry leading solution for mental well-being - 🌎 300.000+ users across 90+ countries - 🤝 Partnered with 200+ licensed psychologists and coaches - 💲 €15M+ venture capital raised from renowned investors - 🎁 Awesome benefits, including unlimited access to our Comprehensive Mental Health App About The Role Kyan Health is building the most advanced AI-augmented mental health and wellbeing platform in Europe. Our mission is to bring high-quality, clinically-grounded psychological support to employees and families across multiple countries, languages, and cultural contexts — with AI playing a central role. We are looking for a Senior Full Stack Engineer with deep AI experience, particularly in: 1. AI agents & multi-step reasoning systems 2. LLM application architectures 3. Tool-calling, retrieval, orchestration, and evaluation 4. Modern AI toolchains and best practices You will work closely with engineering, data, product, and clinical teams to build our AI features end-to-end and help shape the future of our platform. This is a role with massive influence — we’re early enough that your architectural choices, code, and AI expertise will have a lasting impact. Our stack (You don’t need all of this, but strong React/TypeScript + AI foundations are essential.) Frontend - TypeScript - React + Next.js - React Native (plus React Native Web) - Component libraries/design system Backend & Data - Node.js (TypeScript) - Event-driven and service-oriented architecture - BigQuery, PostgreSQL, NoSQL stores - Vector databases, retrieval pipelines - Cloud infra (GCP/Azure) AI Tooling & Ecosystem - OpenAI API & Assistants - Azure OpenAI (GPT, embeddings, structured outputs) - LangChain, LlamaIndex, OpenAI function calling - Agent frameworks (custom, or e.g. LangGraph-style) - Evaluation suites, guardrails, prompt tooling - Monitoring + model observability What You'll do: AI Architecture & Agentic Systems - Design and implement coding agents, task-specific AI agents, and multi-step workflows that power user-facing features. - Build and refine retrieval pipelines, embeddings flows, and hybrid RAG/logic systems. - Architect robust prompting, function-calling, and tool orchestration systems. Full Stack Product Development - Own features across Next.js, backend services, and mobile/web. - Translate product and clinical requirements into AI-powered user experiences. - Work with data pipelines, BigQuery, analytics, and experimentation frameworks. Cross-platform UI Systems - Build and evolve our shared React/React Native component library and design system. - Ensure accessibility, performance, and multi-market language support. Technical Leadership - Set coding standards for AI-integrated features. - Mentor others on AI architecture, LLM patterns, evaluation, and failures modes. - Challenge assumptions, propose better approaches, and push for pragmatic, responsible AI usage. Who We're Looking For Required: - Senior-level engineering experience, ideally 6+ years, with strong autonomy. - Deep understanding of the modern LLM ecosystem: models, embeddings, fine-tuning, structured outputs, evaluation, latency/cost tradeoffs. - Hands-on experience building production AI agents (e.g., planning/multi-step systems, tool-calling, retrieval-integrated workflows). - Strong React + Next.js + TypeScript experience. - Experience building cloud-hosted applications (Azure, GCP, etc.). - Solid backend experience with Node.js, APIs, data modelin...