Senior Full-Stack Engineer

• Design, build, deploy, and support frontend and backend features end to end
• Design and integrate AI-powered features including structured extraction, classification, automation, and agentic workflows
• Validate and evaluate AI outputs and apply human review where appropriate
• Build PostgreSQL data models that support applications and AI features
• Make architecture decisions to keep systems maintainable as they grow
• Build new applications on the modern stack
• Maintain and modernise the established JavaScript platform
• Write tested and reviewed code and verify work before release
• Monitor and troubleshoot production issues
• Work directly with commercial and operational teams to understand processes and shape priorities
• Share knowledge and raise engineering standards

• 6+ years of professional software engineering experience building and running production applications end to end
• Proven experience building AI into production systems or applications, including LLM-based extraction or classification, RAG, or agentic and tool-use workflows
• Ability to make AI output reliable through validation, evaluation, and fallbacks
• Daily use of AI tools in development, with strong habits for checking and reviewing their output
• Strong TypeScript and JavaScript skills
• Modern React experience, including hooks and state management
• Strong Node.js and Express or comparable framework experience
• REST API experience and experience integrating external systems
• Deep PostgreSQL and SQL skills
• Data modelling experience and experience with an ORM or query builder such as Knex, Sequelize, or Prisma
• Comfortable working across modern TypeScript applications and established JavaScript codebases
• Experience with automated testing and code reviews
• High ownership, drive, and ability to raise problems early
• Clear communication with technical and non-technical colleagues
• Bachelor's degree in Computer Science or a related field, or equivalent experience
• Fluent English required
• Based in Hamburg or willing to relocate

• Flat hierarchies and real growth opportunities
• State-of-the-art office setup with adjustable desks, mobile treadmills, air conditioning, and other workplace equipment
• Company pension program with a 30% Buying Labs grant on the employee contribution
• Corporate Benefits membership with discounts from partner brands and retailers
• Full "Deutschlandticket" coverage (ca. €60/month)
• Complimentary "Swapfiets" bike or JobRad bike-leasing with an additional €26/month grant
• Free Friday lunch in the office
• Organic fruit and vegetables, drinks, snacks, coffee/tea, healthy shots, and seasonal treats
• €100 welcome voucher for personalized workspace setup
• Employee referral program with attractive rewards