Senior Java Engineer

Hack The Box (HTB) is the cybersecurity upskilling and talent development platform trusted by individuals, enterprises, and government agencies to sharpen offensive and defensive capabilities. Powered by a vibrant global community and hands‑on, real‑world training, HTB helps security teams practice like attackers, validate skills continuously, and move faster against emerging threats. HTB is scaling rapidly across the enterprise market—especially in Financial Services, MSSPs, and Technology. The company is headquartered in the UK, with additional offices in the US, Australia, and Greece. HTB's entities in the US, UK, and Greece have been certified as a Great Place to Work (2024-2026). The Greek entity has been listed among the Best Workplaces in Greece and Europe for multiple years.

• Solid experience with Java and the Spring ecosystem (Spring Boot, Spring Cloud, Spring Data, Spring Security) in production environments.
• Hands-on experience designing and building microservices, with practical knowledge of patterns like Saga, CQRS, Transactional Outbox, and API Gateway.
• Strong understanding of distributed systems challenges including data consistency, service communication, resilience, and fault tolerance.
• Experience with messaging systems such as Kafka and event-driven architectures.
• Familiarity with containerization and orchestration tools like Docker and Kubernetes, and CI/CD pipelines.
• Ability to communicate architectural decisions clearly through diagrams, documentation, or conversations with technical and non-technical stakeholders.
• Experience mentoring or guiding other engineers.

• Design and build new Spring Boot microservices, applying patterns that ensure consistency, resilience, and scalability.
• Shape the API Gateway layer, enabling secure routing, composition, and cross-cutting concerns for the platform.
• Collaborate with architects and teams to define service boundaries and integration strategies aligned with business needs.
• Modernize legacy systems incrementally using strangler fig and anti-corruption layer patterns.
• Champion code quality through reviews, best practices, and hands-on guidance.
• Partner with SRE, Platform, and QA teams to keep services observable, testable, and production-ready.
• Contribute to architectural decisions, documenting trade-offs and communicating direction clearly.
• Mentor fellow engineers, sharing knowledge on microservices, Spring ecosystem, and clean code practices.

The position is open to candidates located in Greece with hybrid work model for those within 55 km of the Athens office and fully remote for those beyond that radius. Benefits package may vary depending on location and type of employment (e.g., UK, US, Greece, Australia, or engagement through an Employer of Record or contract). Hack The Box is committed to diversity, equity, and inclusion, ensuring all job applications are considered solely based on merit, skills, and qualifications without discrimination.