Senior Java Developer

About the Role Sigma Software is seeking a Senior Java Developer to join the team and work on a cutting-edge security platform. This is a remote role open to candidates across Europe and Ukraine. You will be part of a talented engineering group designing the unified access layer for distributed services to ensure security, scalability, and compliance.

What You'll Do

• Design and evolve the platform access architecture for a large-scale distributed ecosystem
• Build and maintain a unified API layer over multiple distributed services
• Implement fine-grained ABAC authorization at scale, supporting complex hierarchies and relationships
• Develop fail-closed security architectures with strict enforcement guarantees
• Manage regional compliance, data residency, and routing requirements
• Ensure consistent data visibility rules across all products and services
• Design high-performance authorization evaluation systems and policy engines
• Maintain auditability, traceability, and security transparency mechanisms
• Collaborate with platform and product teams on API and access design
• Contribute to architectural decisions and security standards

What We're Looking For

• At least 5+ years of experience building distributed systems
• Strong expertise in Java development
• Experience designing API platforms or API gateways
• Solid background in security architecture and system design
• Experience with authorization systems (RBAC/ABAC or similar)
• Familiarity with cloud-native architectures and scalable, high-availability systems
• Understanding of multi-tenant architectures
• Experience operating complex distributed systems in production
• Strong architectural thinking and problem-solving skills
• Upper-Intermediate or higher English proficiency
• Proactive and detail-oriented
• Thrives in collaborative environments
• Enjoys solving complex integration challenges
• Comfortable experimenting with new technologies
• Committed to improving data systems

Nice to Have

• Experience with Identity and Access Management (IAM) systems
• Experience building API gateways or service mesh architectures
• Work on security-critical or compliance-heavy systems
• Knowledge of policy engines (e.g., OPA)
• Experience with large-scale enterprise platforms
• Familiarity with cloud providers (e.g., GCP)
• Experience with data governance, audit, and compliance systems
• Background in regulated or high-security environments