Senior Full Stack Engineer (f/m/d)

ABOUT USWe are one of the fastest-growing advanced Employee Assistance Program (EAP) and mental wellbeing platforms in the world. Founded in Switzerland in 2021, we support more than 3 million covered lives across 90+ countries, trusted by market-leading multinational enterprises and backed at Series A by Swisscom Ventures, Amplo, and GreyMatter Capital.Our team of 35 individuals of 15+ nationalities is employed directly through our legal entities in Germany, Switzerland, and the US (Texas, Rhode Island, Florida), via Employer of Record (EOR) partners in Canada, Spain, the Netherlands, Belgium, South Africa, Denmark and the UK, and through freelancers in Pakistan and other locations.SOME THINGS WE’RE PROUD OFBuilding an industry leading solution for mental well-being300.000+ users across 90+ countriesPartnered with 200+ licensed psychologists and coaches€15M+ venture capital raised from renowned investorsAwesome benefits, including unlimited access to our Comprehensive Mental Health AppAbout The RoleKyan 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 systemsLLM application architecturesTool-calling, retrieval, orchestration, and evaluationModern AI toolchains and best practicesYou 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.)FrontendTypeScriptReact + Next.jsReact Native (plus React Native Web)Component libraries/design systemBackend & DataNode.js (TypeScript)Event-driven and service-oriented architectureBigQuery, PostgreSQL, NoSQL storesVector databases, retrieval pipelinesCloud infra (GCP/Azure)AI Tooling & EcosystemOpenAI API & AssistantsAzure OpenAI (GPT, embeddings, structured outputs)LangChain, LlamaIndex, OpenAI function callingAgent frameworks (custom, or e.g. LangGraph-style)Evaluation suites, guardrails, prompt toolingMonitoring + model observabilityWhat You'll doAI Architecture & Agentic SystemsDesign 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 DevelopmentOwn 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 SystemsBuild and evolve our shared React/React Native component library and design system.Ensure accessibility, performance, and multi-market language support.Technical LeadershipSet 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 ForRequiredSenior-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 HavePrior 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 UsMake 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 processesInnovative 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 YouFull 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 ProcessCV CheckGet 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 / OfferWe are excited to hear from you!Please note that we do not work with agencies or external recruiters. #J-18808-Ljbffr