Senior Fullstack Engineer

About the RoleWe're a well-funded, fast-growing European AI SaaS startup building an AI-powered phone assistant for small and medium-sized businesses. Our product automates inbound and outbound calls, appointment scheduling, customer service inquiries, and more — operating 24/7 for thousands of companies across the German-speaking market. We take data privacy seriously and run our own proprietary orchestration layer entirely within <Europe.As> a Senior Fullstack Engineer, you'll take end-to-end ownership of product features — from idea and prototype through architecture, implementation, and release — in a remote-first, high-autonomy environment with strong CET overlap.What You'll DoOwn features from discovery and prototyping through architecture, implementation, and production release.Engage directly with customers, partners, and sales to surface real pain points and shape the product <roadmap.Run> product discovery: form hypotheses and validate them with lightweight experiments before committing to large builds.Instrument your area of the product and use metrics to drive data-informed <decisions.Build> pragmatic, scalable software that balances immediate customer value with long-term maintainability.Default to async communication and shipping over excessive meetings.Act with radical ownership — push initiatives forward without waiting for permission.What We're Looking ForRequired (dealbreakers):5+ years of fullstack engineering experience with end-to-end delivery responsibility.Strong hands-on experience with Node.js, TypeScript, NestJS, and React.Native-level German proficiency — essential for supporting our German-language AI product and engaging with customers.Also required:Experience with product discovery: forming and rapidly validating hypotheses through experiments.Comfortable identifying, collecting, and using metrics to support product decisions.Experience collaborating with customers, partners, and sales to define value and surface pain points.Track record of delivering end-to-end customer-facing features from architecture to release.Nice to have:Experience integrating LLMs (e.g., OpenAI) into production applications — a major plus.Experience deploying AI-enabled services on Microsoft Azure in Europe.Familiarity with GDPR and EU AI Act considerations for AI services.Previous experience in a high-growth startup environment.LocationThis is a remote-first role with CET timezone overlap expected. You're also welcome to work from our Vienna office. The role is open to candidates based in Austria or Germany. Visa sponsorship is not available.Compensation & BenefitsSalary range: €80,000 – €120,000 annually, depending on experience.Remote-first culture with high autonomy and minimal <bureaucracy.Work> on a product with real traction, serving thousands of European businesses.Join an early-stage team with significant room to shape the product and engineering culture.