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Taxfix is a fintech company that simplifies tax filing for millions of people across Germany, Spain, and the UK. Since 2016, the company has facilitated over €3.5 billion in tax refunds and operates with a team of 400+ professionals including tax experts, developers, and security specialists.
As a Senior Software Engineer, you will build core features for Taxfix's flagship product, transforming complex tax scenarios into intuitive, reliable user experiences. This is a hands-on role where you'll own work end-to-end—from discovery and technical design through implementation, release, monitoring, and iteration. You'll work in cross-functional teams alongside product, design, and engineering, bringing deep expertise in either frontend or backend development while collaborating effectively across the full stack.
Key responsibilities include:
- Partnering with product management and design to understand customer problems and deliver measurable outcomes
- Owning features end-to-end with accountability for technical decisions and trade-offs
- Contributing to technical direction and long-term product strategy
- Using AI-assisted development tools (for exploration, implementation, testing, debugging, documentation) while critically evaluating outputs and maintaining high engineering standards
- Sharing AI development best practices with teammates and fostering responsible experimentation
- Improving developer experience through tools, automation, and engineering practices that enable reliable, frequent delivery
- Collaborating across product and platform teams in a learning-focused environment
The role emphasizes a builder-first mindset: turning customer problems into shipped outcomes, testing and learning quickly, making pragmatic trade-offs between speed, quality, and maintainability, and treating iteration as progress.
Taxfix offers 30 annual vacation days, flexible working hours, work-from-abroad allowance (up to 6 weeks/year), employee stock options, free mental health coaching, yoga, a monthly wellness allowance, free tax filing through the app, and a dog-friendly office.
REQUIREMENTS:
- Professional software engineering experience with React and Node.js; React Native experience is a plus
- Ability to design reliable backend services and APIs
- Experience working effectively across system boundaries and collaborating with engineers outside your primary specialism
- Proficiency with AI-assisted development tools and ability to evaluate/troubleshoot AI-generated output
- Experience with public cloud environments (Google Cloud, AWS, or Microsoft Azure)
- Familiarity with DevOps concepts and practices (CI/CD, observability, production operations)
- Understanding of core application and backend concepts (authentication, databases, distributed systems, cloud infrastructure, API integrations)
- Builder-first, pragmatic approach with focus on shipped outcomes and clear trade-offs
- Passion for maintainable, elegant code and continuous improvement
- Collaborative, positive attitude with willingness to challenge ideas constructively
- Comfort with ambiguity and ability to thrive in environments still taking shape
