Graduate Role or Internship as a Tech Back-End Developer at a global invoice startup (YC-backed)

About the Company

This fast-growing YC-backed startup is building modern infrastructure to simplify global e-invoicing compliance. Their developer-first API helps businesses automatically generate and submit compliant invoices across multiple countries, reducing complexity and enabling seamless international operations. With a team of experienced engineers and startup operators, they’re focused on solving real-world problems at scale.

The Role

As a Back-End developer, you’ll work on the core systems that power a highly technical, API-first product. You’ll be writing clean, scalable code, contributing to architecture decisions, and working closely with the founding engineering team.

This role is ideal for someone early in their career who wants to learn fast, write meaningful code from day one, and be surrounded by a collaborative and high-calibre team in Madrid. You should be excited about building elegant solutions to messy compliance challenges and about living and growing in a vibrant European tech hub.

What You’ll Do

• Design, build, and maintain backend systems and microservices
• Collaborate on API development and contribute to overall product architecture
• Write clean, well-tested code and participate in code reviews
• Assist with scaling and performance optimisation as the platform grows
• Work closely with front-end and product teams to align on technical needs
• Stay up to date with backend best practices and emerging technologies

Who You Are

• A recent graduate or early-career engineer with a degree in Computer Science or similar
• Experience with modern back-end technologies
• Familiar with APIs, system design, and cloud infrastructure (e.g. Docker, AWS)
• A clear communicator who enjoys working in a team
• Detail-oriented, eager to learn, and excited to grow fast
• English Speaking
• Excited to live and work in Madrid with a collaborative, ambitious team

Job Details

• Location: Madrid
• Type: Full-time
• Salary: Up to 1000 euros a month