Senior Software Engineer – AI-First, Full-Stack Builder

Taxfix; Comunidad de Madrid; On-site; EUR 70,000 - 110,000; Full time

Benefits offered by this job

Free mental health coaching

Yoga

Monthly flex allowance

Employee stock options

30 annual vacation days

Work from abroad up to six weeks

Team social events

Taxfix tax filing support

Dogs in office

Job summary

Taxfix is seeking a Senior Software Engineer to build core features for our flagship product, turning complex tax scenarios into simple, reliable experiences. You will work in a cross-functional team, owning end-to-end delivery from discovery to release while embracing AI-first software development.

You’ll contribute to scalable design and maintainable code, collaborating across frontend and backend with a builder mindset and a passion for quality.

Qualifications

• Proficient in building web apps with React/Node.js and API design.
• Experience delivering reliable frontend or backend services and scalable architectures.
• Familiarity with public cloud platforms (GCP/AWS/Azure) and DevOps practices.
• Ability to use AI-assisted development tools and promote responsible experimentation.

Responsibilities

• Collaborate with product, design, and engineering to solve real user problems.
• Own end-to-end delivery from discovery to release and monitoring.
• Contribute to technical direction and product strategy across the stack.
• Promote high standards in code quality, testing, and documentation.

Skills

React

Node.js

React Native

Public Cloud

CI/CD

APIs

Distributed Systems

Tools

Google Cloud Platform

AWS

Azure

Job description

Taxfix is seeking a Senior Software Engineer to build core features for our flagship product, turning complex tax scenarios into simple, reliable experiences. You will work in a cross-functional team, owning end-to-end delivery from discovery to release while embracing AI-first software development.

You’ll contribute to scalable design and maintainable code, collaborating across frontend and backend with a builder mindset and a passion for quality.