Senior Java Developer (Security Platform)

Google Chrome Microsoft Edge Apple Safari Mozilla Firefox Senior Java Developer (Security Platform)Full-timeCompany DescriptionAre you passionate about building secure, high-performance platforms? We are looking for a Senior Java Developer to join our team and work on a cutting-edge security platform. This is a remote role open to candidates across Europe and Ukraine. At Sigma Software, we create innovative solutions for complex ecosystems, ensuring security, scalability, and compliance at every step. You will be part of a talented engineering group designing the unified access layer for distributed services. Why join us? You will work on a mission-critical project with advanced security architecture, collaborate with skilled professionals, and contribute to a platform that supports global-scale operations.CUSTOMEROur customer is a leading EdTech company that uses AI and data-driven technologies to personalize learning experiences, optimize user engagement, and improve marketing effectiveness through advanced audience targeting and analytics.PROJECTThe project focuses on developing a centralized platform access layer that combines API gateway capabilities, service orchestration, data composition, and fine-grained authorization mechanisms. The platform provides a secure foundation for governance across the ecosystem, supporting complex organizational hierarchies, regional compliance requirements, and consistent policy enforcement.Job DescriptionDesign and evolve the platform access architecture for a large-scale distributed ecosystemBuild and maintain a unified API layer over multiple distributed servicesImplement fine-grained ABAC authorization at scale, supporting complex hierarchies and relationshipsDevelop fail-closed security architectures with strict enforcement guaranteesManage regional compliance, data residency, and routing requirementsEnsure consistent data visibility rules across all products and servicesDesign high-performance authorization evaluation systems and policy enginesMaintain auditability, traceability, and security transparency mechanismsCollaborate with platform and product teams on API and access designContribute to architectural decisions and security standardsQualificationsAt least 5 years of commercial software engineering experienceStrong expertise in Java developmentStrong proficiency in Java 21+ and modern Java features, including virtual threads, NIO, and concurrent programmingHands-on experience building high-performance backend systems with a strong focus on scalability and low latencyExperience working with GraalVM Native Image and optimizing Java applications for native executionSolid understanding of HTTP protocol internals, connection management, streaming, and API performance optimizationExperience processing large volumes of JSON using streaming APIs and memory-efficient techniquesStrong knowledge of performance tuning, profiling, benchmarking, and JVM optimizationExperience designing and implementing caching strategies and cache invalidation mechanismsSolid understanding of authentication, authorization, and security best practices in distributed systemsExperience building or maintaining API gateways, proxies, load balancers, service mesh components, or other infrastructure-level servicesStrong understanding of event-driven architectures and distributed systems designExperience writing comprehensive automated tests for performance-critical and protocol-level componentsUpper-Intermediate or higher English proficiencyWILL BE A PLUSExperience with Netty and high-performance networking applicationsExperience with service mesh technologies such as Istio, Envoy, or DaprHands-on experience with authorization frameworks such as OPA, Cedar, Zanzibar, or OsoExperience with Google Cloud Platform, including Pub/Sub, BigQuery, Memorystore, or RedisExperience deploying and operating applications on KubernetesFamiliarity with gRPC, Protocol Buffers, and HTTP/2Experience working in...