Senior Fullstack Engineer

About The Role We are a fast-growing, seed-stage European AI SaaS company building an AI-powered phone assistant platform used by thousands of small and medium-sized businesses across Europe. Our product automates inbound calls — handling customer inquiries, booking appointments, processing orders, and more — with a strong focus on GDPR compliance and a European-first approach. As a Senior Fullstack Engineer, you will take end-to-end ownership of product features that deliver measurable value to customers. You'll work in a remote-first, high-autonomy environment where shipping and customer impact matter more than meetings. Native-level German proficiency is required for this role, as the product serves German-language markets. What You'll Do Own features from idea and prototype through architecture, implementation, and release. Engage continuously with customers, partners, and sales to surface real pain points. Run product discovery by forming hypotheses and validating them with quick, lightweight experiments. Instrument relevant metrics to enable data-driven decisions in your product area. Build pragmatic, scalable software balancing immediate value with long-term maintainability. Communicate asynchronously where possible and prioritize shipping over excessive meetings. Act with radical ownership — push initiatives forward without waiting for permission. Work remotely with CET overlap, with occasional option to work from the Vienna office. What We're Looking For Required (Dealbreakers): 5+ years of experience in fullstack engineering with end-to-end delivery responsibility. Strong hands-on experience with Node.js, TypeScript, NestJS, and React. Native-level German language proficiency (essential for the product and customer context). Also Required: Experience with product discovery — forming hypotheses and validating them quickly through experiments. Track record of identifying, collecting, and using metrics to support data-driven product decisions. Experience collaborating with customers, partners, and sales to understand pain points and define value. Experience delivering end-to-end software from architecture decisions through to customer-facing releases. Nice to Have: Experience integrating LLMs (e.g., OpenAI) into production software applications. Experience deploying AI-enabled services on Microsoft Azure in European environments. Familiarity with GDPR and EU AI Act considerations for AI services. Prior experience in a high-growth startup environment. Location & Work Arrangement Fully remote — remote-first culture with CET timezone overlap expected. Option to work from the Vienna, Austria office as needed. Visa sponsorship is not available. Compensation & Benefits Salary range: $80,000 – $120,000 USD annually. High-autonomy, low-bureaucracy remote-first work environment. Direct impact on a product used by thousands of European businesses. Work alongside a team with backgrounds at leading enterprise tech and SaaS companies.