Principal Java Engineer en Barcelona, España

We are seeking a Principal Java Engineer with more than 10 years of experience in designing and building Java applications with a proven track record of modernising legacy applications in regulated environments. In this role, you will drive cloud-based transformations, design microservices platforms, and mentor developers through complex technical transitions. Your expertise in cloud, DevOps, microservices, and API design will be critical in migrating customer data and ensuring high-performance, scalable, and compliant solutions. Experience in iGaming is a strong plus.

What will you be doing?

Technical Leadership & Modernisation

• Lead the modernisation of legacy applications , ensuring they meet regulatory standards while improving performance, scalability, and maintainability.

• Design, develop, and deploy cloud-native microservices on AWS.

• Architect high-performance, large-scale applications in Java , optimising for efficiency, reliability, and security.

• Leverage AI to accelrate the refactoring of services.

Cloud & DevOps Transformation

• Drive cloud migration strategies , including lifting, shifting, and refactoring applications for cloud compatibility.

• Implement DevOps best practices , such as CI/CD pipelines, infrastructure as code (IaC), and observability tools (e.g., Prometheus, Grafana, ELK).

• Ensure seamless customer data migration between platforms, maintaining data integrity, security, and compliance.

Microservices & API Development

• Design and implement scalable microservices architectures in Java , leveraging RESTful APIs, with event-driven systems (e.g., Kafka, RabbitMQ).

• Integrate AI-driven solutions to enhance application intelligence, automation, and user experiences.

• Optimise API performance and ensure robust, secure, and well-documented interfaces.

Mentorship & Collaboration

• Mentor junior and mid-level developers, fostering a culture of code quality, innovation, and continuous learning .

• Collaborate with cross-functional teams (e.g., product, security, compliance) to align technical solutions with business goals.

• Lead code reviews, architectural discussions, and troubleshooting to ensure high standards of engineering excellence.

• Strong focus on automation, levergaing pipelines and AI

Compliance & Data Management

• Ensure all solutions adhere to regulatory and security standards (e.g., GDPR, PCI-DSS, or iGaming regulations).

• Implement data protection best practices for managing and migrating customer data in compliance with industry regulations.

• Work closely with legal and compliance teams to mitigate risks and ensure auditability.

Who are you?

• 15+ years of experience in Java and large-scale, high-performance applications (e.g., Spring Boot).

• Proven experience modernising legacy systems in a regulated environment.

• Hands-on expertise in cloud platforms (AWS, Azure, or GCP) and microservices architecture.

• Strong understanding of DevOps , including CI/CD (Jenkins, GitLab CI), containerisation (Docker, Kubernetes), and infrastructure automation (Terraform, Ansible).

• Experience designing and managing APIs and integrating data driven features .

• Experience mentoring developers through technical transformations.

• Familiarity with observability tools (e.g., Prometheus, ELK Stack) and performance tuning.

Nice-to-Have

• iGaming industry experience (e.g., online casinos, sports betting, or fintech for gaming).

• Knowledge of event-driven architectures (Kafka, RabbitMQ) and serverless technologies.

• Knowledge of AI/ML frameworks (e.g., TensorFlow, PyTorch) and their integration into applications.

Why Join Us?

• Work on high-impact, transformative projects that shape the future of our regulated business.

• Collaborate with a talented, forward-thinking team in a dynamic and innovative environment.

• Access to cutting-edge technologies and opportunities for professional growth.

• Competitive salary, benefits, and a culture that values ownership, excellence, and mentorship.

By joining us, you're not only gaining an opportunity to work and collaborate with the best talent in our industry, you’ll also enjoy a range of fantastic perks!

• A competitive and attractive salary

• Private health insurance

• Annual wellbeing benefit allowance

• Social events for building strong relationships with colleagues

About LCKY Group:

LCKY Group brings together a portfolio of leading online casino brands - LuckyCasino, HappyCasino, FlaxCasino, Vera&John, OneCasino and RoyalCasino - alongside its in-house game studio, Swintt. With a strong people-led culture and a proven ability to build and scale in regulated environments, the group is well positioned to accelerate its momentum across key markets.

LCKY Group continues to expand across international markets: Sweden, Finland, Ontario, Chile , as well as in Spain, Denmark and the Netherlands . The Group is home to a diverse and multiskilled workforce, based in a range of locations, including Malta, Stockholm, Sofia, Barcelona, Hoorn, Estepona, Gibraltar and Melilla.

The Group also operates in the B2B vertical through its in-house game development studio, Swintt, which delivers high-quality slot games to operators worldwide.

With an unshakeable belief in its people that’s woven into the company’s DNA, LCKY Group looks boldly to the future with a focus on building appeal in regulated markets.

Learn more about us at

At LCKY Group we firmly believe that our diversity is what makes us unique and that everyone is welcome to enjoy the ride! We are committed to uphold a high level of diversity and inclusion throughout our group.