Senior Java Developer

About the Role

Senior Java Developer to help build a high-load multi-channel communications platform delivering critical notifications to millions of users worldwide. You will work remotely in Sigma Software's international engineering environment, contributing to distributed, event-driven systems with fault-tolerant architecture and real-time processing. What You'll Do

• Design and implement a scalable event-driven communications platform.
• Build highly reliable and fault-tolerant message delivery systems across multi-channel workflows (email, SMS, voice, push).
• Manage large-scale real-time event processing pipelines and ensure observability and performance.
• Design and implement multi-channel delivery pipelines across email, SMS, voice, and push channels; develop provider integrations and external messaging service adapters.
• Handle compliance requirements, consent management, and communication policies.
• Support emergency and high-priority notification workflows with provider failover and resiliency strategies.
• Build tracking, observability, reporting, and analytics infrastructure for delivery status, retries, and engagement events.
• Collaborate with product and engineering teams on communication flows and requirements; contribute to architectural decisions and long-term platform evolution.
• Ensure operational stability, reliability, and maintainability of the system under high load. What We're Looking For
• At least 5 years of software development experience.
• Strong expertise in Java development.
• Experience with distributed systems.
• Strong experience with event-driven architectures.
• Experience with messaging systems, queues, streams, and brokers.
• Experience designing high-scale APIs and backend services.
• Strong understanding of system reliability and fault tolerance.
• Upper-Intermediate English level. Nice to Have
• Experience with email or SMS delivery systems.
• Experience with telecom or messaging infrastructure.
• Experience with marketing automation platforms.
• Experience with notification or engagement systems.
• Experience with workflow engines.
• Experience with compliance-heavy systems, including consent and GDPR-like regulations.
• Experience with high-throughput event processing systems.
• Experience with cloud-native platforms, preferably GCP.