Senior Full Stack Developer (React/FastAPI/Django) - Frontend-Focused

Job Description

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.