Senior Fullstack Engineer

We are a seed/early-stage B2B SaaS company building an AI-powered phone assistant for the German-speaking market. Serving thousands of SMEs across the DACH region, our platform automates customer communication - handling inbound calls, scheduling appointments, transcribing conversations, and integrating with CRMs and calendar tools. We are a remote-first, high-growth team based in Vienna, Austria, and we are looking for a Senior Fullstack Engineer who takes genuine end-to-end ownership of the features they ship., * Own features from initial idea and prototype through architecture, implementation, and production release.

• Engage continuously with customers, partners, and the Sales team to surface real pain points and define meaningful value.
• Run product discovery: form hypotheses and validate them quickly with lightweight experiments before committing to large builds.
• Instrument your area of the product and gather the metrics needed to support data-driven decisions.
• Build pragmatic, scalable software that balances immediate customer value with long-term maintainability.
• Communicate asynchronously and prioritize shipping over excessive meetings.
• Act with radical ownership - push initiatives forward without waiting for permission.

Must-haves (dealbreakers):

• 5+ years of Fullstack Engineering experience delivering end-to-end web features.
• Strong hands-on experience with Node.js, TypeScript, NestJS, and React.
• Native-level German proficiency - essential for working with a German-language AI product and German-speaking customers.

Required:

• Experience with product discovery: forming hypotheses and validating them through rapid experiments.
• Comfortable identifying, collecting, and leveraging metrics to inform product decisions.
• Proven ability to collaborate with customers, partners, and sales teams to understand pain points.
• Track record of delivering customer-facing applications end-to-end, including architecture decisions and release.

Nice to have:

• Experience integrating LLMs (e.g., OpenAI) into production software applications.
• Experience deploying AI-enabled services on Microsoft Azure in a European context.
• Familiarity with GDPR and EU AI Act considerations for AI services.
• Background in high-growth startup environments.

• Salary range: $80,000 - $120,000 USD annually.
• Remote-first setup with optional office access in Vienna, Austria (CET overlap expected).
• High-autonomy, low-bureaucracy environment with direct customer impact.