We are looking for a Senior Full Stack Developer with a strong frontend focus to join a fast-growing product company building AI-powered solutions for small and medium-sized businesses. You will work in a senior, highly autonomous engineering team, taking ownership of features from concept to production while helping shape both the product experience and technical direction. Responsibilities Own and deliver complex features across the entire application stack. Lead frontend development initiatives and continuously improve user experience, usability, and visual quality. Design and implement scalable, maintainable, and production-ready React applications. Collaborate with product and engineering stakeholders to define technical solutions and architecture. Extend and maintain Python-based backend services using FastAPI and Django. Analyze user flows, edge cases, and failure scenarios before implementation. Contribute to architectural discussions, technical decisions, and code quality improvements. Utilize AI-assisted development tools as a core part of the engineering workflow. Take full ownership of features throughout their lifecycle, from planning to deployment. Requirements Proven experience delivering complex software projects in a professional environment. Strong expertise in React and modern frontend development practices. Experience building accessible, responsive, and high-quality user interfaces. Solid full-stack development experience with Python-based backends. Hands-on experience with FastAPI and/or Django. Strong understanding of software architecture, system design, and engineering best practices. Experience working in startup or fast-paced product environments. Ability to work independently and take ownership of technical decisions. Practical experience using AI-powered development tools such as Cursor, Claude Code, GitHub Copilot, Codex, or similar. Strong English communication skills. Will Be a Plus Experience building AI-native products or agentic AI systems. Familiarity with LLM-based applications and AI workflows. Experience working with PostgreSQL and AWS. Background in B2B SaaS or fintech products. Knowledge of German accounting systems and standards. German language skills. What We Offer Competitive compensation package. Health insurance coverage. Paid vacation and public holidays. Flexible work environment with a high level of autonomy. Access to modern AI-powered development tools. Opportunity to influence product and technical decisions.