Senior Fullstack Engineer

ABOUT THE ROLE This is a Senior Fullstack Engineer role at a fast-growing European AI voice assistant company serving small and medium-sized businesses. You will take end-to-end ownership of product features, from early discovery and prototyping through to architecture, implementation, and release, in a remote-first environment with a strong product and customer focus. WHAT YOU'LL DO - Own features across the full product lifecycle: idea, prototype, architecture, implementation, and release. - Engage regularly with customers, partners, and Sales to surface real pain points and define value. - Run product discovery by forming hypotheses and validating them quickly through lightweight experiments. - Instrument your areas of ownership and gather metrics to support data-driven decisions. - Build pragmatic, scalable software that balances immediate value with long-term maintainability. - Communicate asynchronously and prioritize shipping over excessive meetings. - Act with radical ownership and drive initiatives forward independently. WHAT WE'RE LOOKING FOR - 5+ years of experience in fullstack engineering with end-to-end delivery responsibility for customer-facing web applications. - Strong hands-on experience with Node.js, TypeScript, NestJS, and React; substantial frontend and backend coverage is required. - Experience with product discovery: forming hypotheses and validating them quickly through experiments. - Comfortable identifying, collecting, and using metrics to inform product decisions. - Skilled at collaborating directly with customers and partners to extract actionable insights. - Native-level German proficiency is required; fluent English is also expected for team communication. - Experience integrating LLMs (such as OpenAI) into production software is a strong plus. - Familiarity with GDPR and EU AI Act considerations for AI-powered services is a plus. - Experience working in a high-growth startup environment is a plus. - Strong CS fundamentals and sound judgment around effort, quality, and speed trade-offs. COMPENSATION & BENEFITS Salary range: 80,000 to 120,000 EUR annually. Visa sponsorship is not available. LOCATION Fully remote, with a preference for candidates based in Germany or Austria and availability during Central European Time hours. Occasional in-person collaboration in Vienna is possible.