Senior Fullstack Engineer

Job Description

Job Description

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.

• 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.

• 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.

• 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.

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.