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: AI agents & multi-step reasoning systems LLM application architectures Tool-calling, retrieval, orchestration, and evaluation 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 modeling, auth, performance. Familiarity with BigQuery or similar analytical data warehouses. Strong product awareness — focus on usability, clarity, and delivering outcomes. Pragmatic engineering mindset: readable code, clear patterns, low complexity. Nice to Have: Prior work in healthtech , HR tech, or other sensitive domains. Experience with evaluation frameworks , AI observability, or human-in-the-loop workflows. Background in mobile development (React Native, native iOS/Android). Experience with multi-language or multi-market products. Why Join Us Make an Impact: Your work will directly contribute to improving mental health in workplaces around the world. Ownership: You'll have the chance to take ownership of our content production processes Innovative Environment: Work in a greenfield space where your ideas aren't just welcome—they're essential. Collaborative Team: Join a supportive team where collaboration and innovation are at the heart of what we do. We are an easy to work with & low ego team, and want to keep it like that. What's In It For You Full Access to Our Comprehensive Mental Health App: Unlimited use of Kyan Health's AI well-being companion "KAI" and guided meditation courses. Unlimited sessions with licensed psychologists. Unlimited sessions with ICF-certified coaches. Competitive compensation , adjusted for experience. Meaningful stock options in a rapidly growing AI-driven healthtech company. Work with a mission-driven team and product that genuinely helps people. Hybrid in Berlin or remote within CET±4. Autonomy, ownership, and a chance to shape foundational AI systems from the ground up. Interview Process: CV Check Get to know Kyan, Girish (30 minutes Call) Get to know your manager, Nacho (45 minutes Call) Team Interview(s), ( 30 minutes each call) Online or Onsite Live Coding Exercise (Nacho/Team, 120 minutes) Offer Stage: Meet the founder(s) (30 minutes) / Reference check / Offer Please note: We only accept applications submitted through our official Careers Page. Applications submitted via other channels will not be considered. 🤩We are excited to hear from you! ⛔Please note that we do not work with agencies or external recruiters.