Senior Software Engineer – Madrid

? Madrid, Spain | Hybrid – 1 day per week on-site / 4 days working from home

? €55,000–€75,000 gross annual salary + bonus

We are working with a fast-growing international SaaS and finance business that is scaling its engineering team in Madrid.

As part of this growth, the company is looking to hire 3 Senior Software Engineers and 1 Lead Software Engineer to join its expanding technology function.

This is an exciting opportunity to join an international engineering environment where you will work on a highly scalable SaaS platform, taking ownership of backend services and contributing to architecture, product development and technical improvements.

The role is hands-on and suited to an experienced engineer who combines strong Java and Spring Boot expertise with good engineering judgement, product thinking and a commitment to building secure, reliable and maintainable software.

Key responsibilities

- Design, build and maintain scalable services using Java, Spring Boot and .NET/C# .
- Own features and services from technical design through deployment and production operation.
- Translate product requirements into pragmatic, maintainable technical solutions.
- Design REST APIs, data models and asynchronous integrations for a multi-tenant SaaS platform.
- Contribute to architectural decisions and constructively challenge proposals where risks or better alternatives are identified.
- Write clean, secure and well-tested code.
- Participate actively in code and design reviews.
- Improve platform reliability, performance, observability and maintainability.
- Diagnose production issues, identify root causes and implement lasting improvements.
- Help modernise existing services and manage technical debt.
- Use AI-assisted development tools responsibly to improve development,



testing, documentation and problem-solving.
- Share knowledge and support the development of other engineers.
- Collaborate closely with Product Managers, QA Engineers and wider technical teams.

Experience required
- 4+ years of professional software engineering experience , including ownership of production backend systems.
- Strong hands-on experience with Java and Spring Boot and .NET/C# .
- Experience designing and consuming RESTful APIs.
- Strong knowledge of relational databases, data modelling and SQL.
- Hands-on experience with JavaScript and React .
- Solid understanding of modern front-end development practices and component-based architectures.
- Experience with automated unit, integration and API testing .
- Experience with Git, code review and CI/CD practices .

Nice to have
- Experience with AWS and cloud-native applications .
- Experience with Docker and Kubernetes .
- Knowledge of microservice and modular monolith architectures.
- Experience with event-driven systems, Kafka or AWS SQS .
- Experience with MongoDB or other non-relational databases.
- Knowledge of observability, monitoring, alerting and incident response.

What’s on offer?
- €55,000–€75,000 gross annual base salary , depending on experience and technical knowledge.
- Bonus scheme.
- 25 days' holiday + your birthday off.
- Employee share option scheme.
- Flexible working and a hybrid working model – just 1 day per week on-site in Madrid and 4 days working from home.
- Versátil perks package.
- Opportunity to join an international business with teams across Spain and the UK.
- Diverse, inclusive and collaborative working environment.
- The opportunity to work on an innovative SaaS platform within the embedded finance/fintech space.

Apply now or get in touch for a confidential conversation.

📌 Senior Software Engineer (Madrid)
🏢 Connect-AI
📍 Madrid