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Taxfix is a fintech company that has helped millions of people file taxes confidently and claim refunds. Operating across Germany, Spain, and the UK with over 400 professionals, the company has facilitated more than €3.5 billion in tax refunds since 2016.
As a Senior Software Engineer, you will build core features for the flagship product, transforming complex tax scenarios into simple, reliable user experiences. You'll adopt a builder-first mindset: staying close to customer problems, leveraging AI and modern engineering tools to move quickly from idea to impact, and taking ownership of outcomes.
You will work hands-on in a cross-functional team, bringing deep expertise in either frontend or backend engineering while collaborating effectively across the stack. You'll help raise the bar for scalable design, quality, maintainability, and AI-first software development.
Key responsibilities include:
- Partnering with product, design, and engineering to understand customer problems and deliver measurable outcomes
- Owning work end-to-end: discovery, technical design, implementation, release, monitoring, and iteration
- Converting ambiguity into action, making sound trade-offs, and delivering valuable increments without compromising long-term maintainability
- Contributing to technical direction and strategy supporting the product vision
- Using AI-assisted development tools daily to accelerate exploration, implementation, testing, debugging, and documentation while maintaining high standards
- Critically evaluating and validating AI-generated output, using effective prompting and appropriate safeguards
- Sharing AI-assisted development practices and helping teammates improve their use of AI tools
- Improving developer experience through tools, automation, and engineering practices enabling reliable, frequent delivery
- Collaborating across product and platform teams in an environment where people learn, grow, give constructive feedback, and raise challenges safely
The company offers 30 annual vacation days, flexible working hours, work-from-abroad opportunities (up to six weeks annually), employee stock options, free mental health coaching, yoga, a monthly allowance for services, free tax filing through the Taxfix app, and a dog-friendly office.
REQUIREMENTS:
- Professional software engineering experience with React and Node.js; React Native experience is a plus
- Ability to work effectively across system boundaries and collaborate with engineers outside your primary specialism
- Proficiency using AI-assisted development tools in daily work while maintaining high engineering standards
- Ability to evaluate and troubleshoot AI-generated output, use effective prompting, and share practical learnings
- Experience with public cloud environments (Google Cloud, AWS, or Microsoft Azure)
- Familiarity with DevOps concepts and practices including CI/CD, observability, and operating software in production
- Understanding of core application and backend concepts: authentication, databases, distributed systems, cloud infrastructure, and API integrations
- Builder-first, pragmatic approach: turning customer problems into shipped outcomes, taking initiative, testing and learning quickly, making clear trade-offs between speed, quality, maintainability, and risk
- Passion for writing maintainable, elegant code and continuously improving how software is built
- Collaborative, positive attitude with willingness to challenge ideas constructively
- Builder mindset: thriving in environments still taking shape, taking initiative to move ideas forward, creating impact even when the path isn't fully defined
- Comfort with trying things out over waiting for perfect conditions, shipping early to learn fast, and treating iteration as progress
