Senior Fullstack Engineer
About the Role
We are an angel-backed AI SaaS startup building a German-language AI phone assistant used by thousands of European businesses. Our small, high-growth team operates in a remote-first environment with strong CET overlap, and we are looking for a Senior Fullstack Engineer who thrives on end-to-end ownership — from idea through architecture, implementation, and release. This role sits at the intersection of engineering and product: you will engage directly with customers, run experiments, and ship features that deliver measurable value. Native-level German proficiency is required, as our product and many of our customers operate in German.
What You'll Do
Own features end-to-end — from prototype and architecture decisions through to customer-facing release. Engage continuously with customers, partners, and the sales team to surface real pain points and translate them into product improvements. Run product discovery by forming hypotheses and validating them with lightweight experiments before building large systems. Instrument and track the metrics relevant to your area to enable data-driven decisions. Build pragmatic, scalable software that balances immediate customer value with long-term maintainability. Communicate asynchronously where possible and prioritize shipping over excessive process. Act with radical ownership — push initiatives forward without waiting for permission. Work remotely with CET overlap, or from the Vienna office as needed. What We're Looking For 5+ years of full-stack engineering experience delivering end-to-end web features. Strong proficiency in Node.js, TypeScript, NestJS, and React. Native-level German proficiency — non-negotiable for this role. Product mindset: you measure success by customer value, not lines of code. Experience with product discovery — forming hypotheses and validating them quickly through experiments. Comfortable owning analytics, tracking, and data to support product decisions. Experience collaborating directly with customers, partners, and sales to define value and understand pain points. Strong CS fundamentals and sound judgment on effort/quality/speed trade-offs. Nice to have: Experience integrating LLMs (e.g., OpenAI) into production applications — a significant plus. Experience deploying AI-enabled services on Microsoft Azure in Europe. Familiarity with GDPR and EU AI Act considerations for AI services. Prior experience in a high-growth startup environment. Compensation & Benefits Salary: $80,000 – $120,000 USD annually (or equivalent), depending on experience. Remote-first culture with strong async communication norms. Small, high-ownership team where your impact is visible and meaningful. Location Fully remote with CET timezone overlap preferred. The team is headquartered in Vienna, Austria; occasional in-office collaboration is possible. Visa sponsorship is not available — candidates must already have the right to work in the relevant jurisdiction.