Senior Founding Product Engineer

About the Role Join a fast growing AI powered B2B SaaS startup as a founding product engineer, collaborating with a small team to ship end to end features for a German focused AI phone assistant used across Europe. You will own initiatives from idea to production and help scale the product and its adoption. What You'll Do Own features end to end from hypothesis to production for products used by thousands of companies in Europe. Lead product discovery by testing hypotheses through rapid experiments. Maintain close contact with customers, partners, and Sales to surface real pain points. Design and implement tracking to enable data driven decisions. Build software across the stack and drive architecture choices through release. Prioritize pragmatic solutions balancing immediate validation with long term scalability. Run experiments and lightweight prototypes before large scale commitments. Take ownership and move initiatives forward without waiting for sign offs. What We're Looking For 3+ years of product engineering experience delivering features end to end. Full stack experience with Node.js, TypeScript, NestJS, and React. Experience integrating or working with large language models is a strong plus. German language proficiency at B2 level or above, with English for team and product communication. Hands on experience owning software architecture through production release. Comfort in a startup environment and a pragmatic, data driven mindset. Experience extracting and owning relevant metrics to iterate based on data. Compensation & Benefits Salary range €80K-€120K annually. Equity available in a high growth environment. Visa sponsorship: not provided. Location Work arrangement: remote first, with CET overlap; optional office access in Vienna. Primary location: Germany.