Senior Java Engineer (Segmentation & Audience Platform)

We at Sigma Software are looking for a Senior Java Engineer to join an exciting project in the domain of audience segmentation and engagement. This is a remote role open to candidates from Ukraine and Europe, offering the opportunity to work with cutting-edge technologies and high-scale systems. You will be part of a team building a real-time platform that powers communications, personalization, automation, and customer engagement across diverse ecosystems. At Sigma Software, we value innovation, collaboration, and technical excellence. Why join us? You’ll work on challenging tasks, contribute to architectural decisions, and have the freedom to experiment with new technologies while improving data systems at scale. CUSTOMER Our 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. PROJECT The project is a real-time platform that enables product teams and business stakeholders to define and manage dynamic user groups based on user attributes, relationships, behavioral events, and historical activity. Design and implement core components of the audience segmentation platform Develop and evolve a flexible segment definition language supporting complex targeting scenarios Build scalable evaluation engines for processing large-scale entity and relationship data Implement relationship-based audience resolution across multiple entity types Optimize incremental recomputation for continuous data changes Create event-driven pipelines for real-time segment accuracy Ensure governance, auditability, and lifecycle traceability of segments Design low-latency resolution services for high-scale operations Develop caching strategies for dynamic segments and snapshots Optimize system performance, scalability, and operational efficiency Collaborate with product and engineering teams to define platform capabilities and architecture Provide technical leadership and contribute to architectural decisions At least 5 years of commercial software engineering experience Strong Java expertise Solid understanding of streaming architectures and stateful stream processing using technologies such as Apache Beam, Apache Flink, Kafka Streams, or Spark Structured Streaming Strong experience designing and building rule engines, expression evaluators, query engines, or policy/targeting systems Hands-on experience with incremental computation and materialized view maintenance Experience designing event-driven distributed systems with a strong focus on scalability and reliability Strong knowledge of data consistency concepts, including point-in-time snapshots, exactly-once processing, idempotency, bounded staleness, and eventual consistency Experience building dependency graphs, composition engines, or DAG-based processing pipelines Practical experience with distributed data stores and low-latency data modeling Strong knowledge of Java and Google Cloud Platform, including Pub/Sub and Apache Beam Experience building correctness-critical systems with a strong focus on testing, validation, and fault tolerance Solid understanding of versioning, rollback strategies, anomaly detection, and production safety practices Upper-Intermediate English level WILL BE A PLUS Experience with AdTech, MarTech, CRM segmentation, audience-building, or campaign targeting platforms Experience with query optimization, indexing strategies, and database internals Knowledge of graph processing, relationship traversal, or projection-based systems Experience with multi-tenant architectures, workload isolation, and cost optimization Understanding of GDPR-compliant data deletion and privacy propagation Experience working in regulated domains such as Education (K-12), Healthcare, or FinTech Experience with Google Cloud Spanner or similar globally distributed databases Familiarity with geospatial indexing and location-based querying PERSONAL PROFILE Proactive and detail-oriented Thrives in collaborative environments Enjoys solving complex integration challenges Comfortable experimenting with new technologies Committed to improving data systems