Software Developer C# .Net Core API SQL

Software Developer / Engineer (C# .Net Core API SQL) Madrid to €80,000

Are you a backend focussed Software Developer with strong C# skills?

You could be progressing your career in a senior, hands-on Software Developer role, working on a major rebuild of a leading international payments platform.

As a Software Developer you’ll join a small, autonomous engineering team of around 4-6, including QA and a Team Lead, helping to modernise backend services and build the next generation of the platform. This is a hands-on role with genuine technical ownership, where you’ll lead the delivery of new capabilities and contribute to the evolution of the underlying architecture.

You’ll design and implement robust, scalable APIs and backend services using C# .Net Core, leading new features and technical projects from design through to production, applying strong system design and architectural principles across microservices and event driven environments.

You’ll design and optimise SQL databases and queries, maintain high standards of automated testing and work with AWS and other cloud platforms in production. You’ll also use AI development tools such as Claude and GitHub Copilot to improve engineering productivity, while mentoring other engineers and contributing to technical best practice.

Location / WFH:

You join colleagues in the Madrid office 2-3 days a week, with flexibility to work from home the other days.

About You

• You have strong C# .Net Core backend development experience
• You have experience building production APIs
• You have good SQL skills
• You have experience with system design, software architecture, microservices and event driven systems
• You’re comfortable working with cloud infrastructure in production; AWS preferred
• You have experience mentoring engineers and sharing technical knowledge
• You have hands-on experience using AI coding / development tools such as Claude or Copilot
• Finance / payments experience is desirable, but not essential
• You have fluent English language skills

What’s In It For You

• Salary to €80,000
• Bonus
• 23 days holiday, rising to 28 + your birthday off
• Pension, Life Assurance, Income Protection, Critical Illness Cover
• Healthcare
• Hybrid working
• Career development

• You have strong C# .Net Core backend development experience
• You have experience building production APIs
• You have good SQL skills
• You have experience with system design, software architecture, microservices and event driven systems
• You’re comfortable working with cloud infrastructure in production; AWS preferred
• You have experience mentoring engineers and sharing technical knowledge
• You have hands-on experience using AI coding / development tools such as Claude or Copilot
• Finance / payments experience is desirable, but not essential
• You have fluent English language skills

• Salary to €80,000
• Bonus
• 23 days holiday, rising to 28 + your birthday off
• Pension, Life Assurance, Income Protection, Critical Illness Cover
• Healthcare
• Hybrid working
• Career development