Staff Software Engineer – AI-Driven Tax Platform, Full-Stack

Taxfix; Comunidad de Madrid; On-site; EUR 90,000 - 140,000; Full time

Benefits offered by this job

Mental health coaching

Yoga

Monthly flex allowance

Stock options

30 vacation days

Work from abroad

Team meetups

Dog-friendly office

Job summary

Taxfix in Madrid is seeking a Staff Software Engineer to build core features for our flagship product, turning complex tax scenarios into simple, reliable experiences. You will own end-to-end work in a cross-functional team, with a strong emphasis on AI-assisted engineering and maintainable design across frontend and backend systems.

You will collaborate across product and platform teams, ensuring scalable architecture, quality, and rapid delivery while promoting responsible AI practices and

Qualifications

• Professional software engineering experience with React and Node.js.
• Experience designing reliable backend services and APIs.
• Experience with React Native is a plus.
• Familiarity with public cloud environments (GCP, AWS, Azure).
• Knowledge of DevOps concepts including CI/CD and observability.

Responsibilities

• Partner with product management, design, and engineering to understand customer problems and deliver measurable outcomes.
• Own work end to end—from discovery and technical design through implementation and release.
• Turn ambiguity into action and deliver valuable increments with maintainability in mind.
• Contribute to technical direction and strategy to support long-term product vision.
• Use AI-assisted development tools to accelerate exploration, implementation, testing, and documentation.
• Evaluate and troubleshoot AI-generated output and share practical learnings.
• Improve developer experience through tooling and practices for reliable delivery.
• Collaborate across product and platform teams and foster a learning environment.

Skills

React

Node.js

React Native

AI tooling

Cloud platforms

CI/CD

Tools

CI/CD pipelines

Kubernetes

Job description

Taxfix in Madrid is seeking a Staff Software Engineer to build core features for our flagship product, turning complex tax scenarios into simple, reliable experiences. You will own end-to-end work in a cross-functional team, with a strong emphasis on AI-assisted engineering and maintainable design across frontend and backend systems.

You will collaborate across product and platform teams, ensuring scalable architecture, quality, and rapid delivery while promoting responsible AI practices and