Senior Software Engineer

We are looking for a Senior Software Engineer to join our early team and help build the core platform of a startup transforming Audit 4.0 and control management for companies.

At Byld, we don't just build businesses—we create game-changing ventures in collaboration with leading corporations. Since 2017, we've been designing, validating, and launching new companies, blending the best of the entrepreneurial and corporate worlds to develop scalable businesses with real impact.

Our latest venture, Ermine, was born from this vision. Built alongside Erhardt, Ermine is a cutting-edge SaaS platform that simplifies and enhances Risk Management, Audit Management, ESG Management, Quality Management, and Regulation & Standards. It centralizes everything in one place, automating evidence collection, ensuring traceability, and increasing operational efficiency—all while saving time, resources, and costs.

Many companies still struggle with manual processes, scattered information, and compliance challenges. Ermine eliminates these pain points by automating evidence collection, ensuring traceability, and increasing efficiency—all while saving time and resources.

Join us in revolutionizing risk and control management for SMEs.

We are looking for a Senior Software Engineer (Full Stack) to play a key role in the evolution of Ermine's platform.

You will work on core architectural decisions, build end-to-end product features, and help shape how the platform scales in terms of performance, data volume, and complexity. You'll collaborate closely with Product, founders, and other engineers, balancing speed with robustness in a real production environment.

You will work across backend and frontend, with a strong focus on Java/Spring microservices and Angular, contributing to the next major version of Ermine and laying solid foundations for future growth.

Start Date

01/03/2026

Contract Duration

Permanent

As Senior Software Engineer, you will:

• Design, build, and maintain core backend microservices using Java and Spring Boot.
• Develop end-to-end features, from database and APIs to frontend interfaces.
• Contribute to architectural decisions around scalability, performance, and reliability.
• Build and evolve the frontend experience in Angular, focusing on usability and performance.
• Work with asynchronous communication patterns and event-driven flows where appropriate.
• Ensure high code quality through testing, reviews, and clean code practices.
• Collaborate closely with Product to translate business and compliance requirements into technical solutions.
• Diagnose and resolve complex technical issues related to data volume, concurrency, or integrations.
• Participate in CI/CD, containerization, and deployment processes.
• Mentor junior and mid-level developers and actively contribute to technical discussions and improvements.

Technical challenges you'll tackle

You'll face real, production-grade challenges that require thoughtful design and senior-level decisions, such as:

• Building a new frontend for the next version of Ermine. Designing and developing a new front-end experience that will become the foundation of the platform's next phase. This includes rethinking user flows, performance, maintainability, and how complex compliance workflows are presented in a clear and usable way. While this is a full-stack role, strong front-end ownership is essential.
• Scaling data-intensive workflows. Handling millions of evidences and audit records while keeping performance predictable and queries efficient.
• Evolving a microservices architecture. Reducing tight coupling between services, moving towards more event-driven patterns, and improving system resilience.
• Designing for complex state and traceability. Managing workflows, audit trails, and historical states without sacrificing consistency or performance.
• Modernizing a growing platform. Contributing to incremental migrations of core technologies while keeping the platform stable for real customers.

These challenges are central to the product and have direct impact on customer experience, scalability, and long-term maintainability.

Our stack

We work with a modern, evolving stack designed for complex, regulated environments:

• Backend: Java, Spring Boot, microservices, REST APIs, relational databases (PostgreSQL), asynchronous messaging
• Frontend: Angular, TypeScript, reactive patterns, modular UI components
• Infrastructure: Docker, Kubernetes, CI/CD pipelines
• Security: OAuth2 / OpenID Connect, JWT-based authentication and authorization

You don't need to master every tool on day one, but you should feel comfortable navigating this ecosystem and growing with it.

You are a senior engineer who enjoys building complex systems and taking ownership. You feel comfortable operating in environments where not everything is defined yet, and you like shaping solutions rather than just implementing tickets.

You likely have:

• Degree in Computer Science, Software Engineering, or a related technical field.
• Higher Vocational Training (CFGS) in Web or Multiplatform Application Development, with equivalent proven professional experience, is also valid.
• 3+ years of experience developing production-grade software.
• Strong experience with Java (8+) and Spring Boot, including REST APIs and microservices.
• Solid knowledge of relational databases, especially PostgreSQL.
• Experience building frontend applications with Angular and TypeScript.
• Familiarity with asynchronous systems, messaging, or event-based architectures.
• Hands-on experience with Docker, Git, and CI/CD pipelines.
• A good understanding of software design principles, testing, and clean code.
• The ability to communicate clearly with both technical and non-technical stakeholders.
• A collaborative mindset and willingness to give and receive feedback.

Above all, you care about building robust, maintainable software that solves real problems.

Desirable

• Experience with Kubernetes and cloud-native environments.
• Background in regulated domains (compliance, finance, healthcare, public sector).
• Knowledge of security, authentication, and authorization.
• Experience scaling systems with high data volumes or complex workflows.
• Interest in software architecture, performance optimization, or technical leadership.
• Master's degree in Software Engineering, Big Data, Cybersecurity, or similar fields.

• Technical certifications such as:

• Oracle Certified Professional Java SE

• Spring Professional Certification
• Kubernetes Certified Application Developer (CKAD)
• AWS Certified Solutions Architect (or equivalent in Azure / GCP)
• Security-related certifications (e.g. CEH or similar)
• Knowledge or hands-on experience with Artificial Intelligence, including practical use of AI-assisted development tools or intelligent features in products.
• Familiarity with MCP or similar approaches to integrating AI models, tools, and context-aware systems into software products.

• A competitive salary.
• Permanent contract and long-term growth perspective.
• Flexible working model (hybrid).
• Becoming an entrepreneur with the support of the first Spanish Corporate Venture Builder and an industry-leading company, Erhardt.
• Actively participate in the disruption of the new era of Control Management.
• Commitment and support of Erhardt and Byld's liquid building team.
• Experienced, motivated, and multidisciplinary team and board of directors.
• Direct collaboration with Product, founders, and industry experts.
• Be part of Byld's ecosystem, a team of teams capable of building new ventures from zero to one
• The opportunity to work on a product with real regulatory and societal impact.