Senior Software Engineer

Our story:

Every year millions of people are either filing their taxes in fear or giving up on their tax refund altogether. We're working on fixing that. Our intuitive app enables anyone, regardless of education or background, to file their taxes with newfound confidence.

Spread across Germany, Spain and the UK, the team at Taxfix Group with its brands Taxfix and Steuerbot, is a compassionate group of solution-finders. We speak our minds openly, and with over 400 professionals, including tax experts, developers, and IT security experts, we're rich in ideas and voices. The group has facilitated more than 3.5 billion euros in tax refunds for its customers since its founding in 2016.

The opportunity:

This role is based in Madrid, and requires at least 1 day a week in office presence as we work on a hybrid model.

As a Senior Software Engineer, you’ll build core features for our flagship product, turning complex tax scenarios into simple, reliable experiences. You’ll bring a builder-first mindset: staying close to customer problems, using AI and modern engineering tools to move from idea to impact quickly, and taking ownership of outcomes—not just code.

You’ll work hands-on in a cross-functional team and bring deep expertise in either frontend or backend engineering, while collaborating effectively across the stack. You’ll help us raise the bar for scalable design, quality, maintainability, and AI-first software development.

Your responsibilities:

• Partner with product management, design, and engineering to understand customer problems, shape pragmatic solutions, and deliver measurable outcomes.

• Own work end to end—from discovery and technical design through implementation, release, monitoring, and iteration.

• Turn ambiguity into action, make sound trade-offs, and deliver valuable increments without compromising long-term maintainability.

• Contribute to technical direction and strategy in support of the long-term product vision.

• Use AI-assisted development tools in your daily engineering work to accelerate exploration, implementation, testing, debugging, and documentation while maintaining high engineering standards.

• Critically evaluate, validate, and troubleshoot AI-generated output, using effective prompting and appropriate safeguards rather than accepting results at face value.

• Share effective AI-assisted development practices, encourage responsible experimentation, and help teammates improve how they use AI tools.

• Improve developer experience through tools, automation, and engineering practices that enable reliable, frequent delivery.

• Collaborate across product and platform teams, and contribute to an environment where people learn, grow, give constructive feedback, and raise challenges safely.

Your profile:

• Professional software engineering experience (React, Node.js) and designing reliable backend services and APIs. Experience with React Native experience is a plus.

• Able to work effectively across system boundaries and collaborate with engineers outside your primary specialism.

• Use AI-assisted development tools in your daily engineering work to accelerate exploration, implementation, testing, debugging, and documentation while maintaining high engineering standards.

• Able to evaluate and troubleshoot AI-generated output, use effective prompting where relevant, and share practical learnings with teammates.

• Experience working with a public cloud environment such as 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 such as authentication, databases, distributed systems, cloud infrastructure, and API integrations.

• A builder-first, pragmatic approach: You turn customer problems into shipped outcomes. You take initiative, test and learn quickly, and make clear trade-offs between speed, quality, maintainability, and risk.

• Passion for writing maintainable, elegant code and continuously improving how software is built.

• A collaborative, positive attitude and a willingness to challenge ideas constructively.

• You have a builder mindset. You thrive in environments where things are still taking shape, take initiative to move ideas forward, and find ways to create impact even when the path isn't fully defined.

• You embrace trying things out over waiting for perfect conditions, ship early to learn fast, and treat iteration as progress.

• You are able to be based in Madrid and work on a hybrid model ( 1 day per a week )

Why Taxfix?

• A chance to do meaningful, people-centric work with an international team of passionate professionals.

• Holistic well-being with free mental health coaching sessions and yoga.

• A monthly allowance to spend on an extensive range of services that you can use and roll over as flexibly as you like.

• Employee stock options for all employees—because everyone deserves to benefit from the success they help to create.

• 30 annual vacation days and flexible working hours.

• Work from abroad for up to six weeks every year. Just align with your team, and then enjoy your trip.

• Plenty of opportunities to socialise as a team. In addition to internal tech meetups, our international team hosts regular get-togethers—virtually and in person when possible.

• Free tax declaration filing, of course, through the Taxfix app—and internal support for all personal tax-related questions.

• Have a four-legged friend in your life? We’re happy to have dogs join us in the office.

Excited? So are we. Check out our Life at Taxfix page on LinkedIn to get a glimpse of our culture.

At Taxfix, we believe that incredible things happen when you have a wealth of perspectives and experiences. We're proudly committed to equal employment and development opportunities no matter your gender, race, religion, age, sexual orientation, colour, disability, or place of origin. To help mitigate any potential unconscious biases, we ask that you refrain from including your picture, age, or marital status on your CV. Let your experiences speak for themselves.

Not sure if you meet all the requirements for this role? Please apply anyway. You might bring something special to the team that we hadn't considered previously.