Sigma Software

Discussion

Senior Java Developer

Summary

Designs and builds a high-scale, event-driven messaging platform handling email, SMS, voice, and push notifications with strong focus on reliability, compliance, and fault tolerance.

  • Design and implement a scalable event-driven communications platform
  • Build highly reliable and fault-tolerant message delivery systems
  • Manage large-scale real-time event processing pipelines
  • Design and implement multi-channel delivery pipelines across email, SMS, voice, and push channels
  • Handle compliance requirements, consent management, and communication policies
  • Support emergency and high-priority notification workflows
  • Implement provider failover and resiliency strategies to ensure delivery continuity
  • Build tracking systems for delivery status, retries, and engagement events
  • Design and implement observability, reporting, and analytics infrastructure
  • Develop event processing and message orchestration workflows
  • Implement provider integrations and external messaging service adapters
  • Ensure system scalability, throughput, and performance under high load
  • 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
  • At least 5 years of commercial software engineering experience
  • Strong experience in Java development
  • Proven experience designing and building high-scale messaging, notification, or communication platforms supporting email, SMS, push, or voice channels
  • Strong experience integrating with CPaaS and messaging providers such as Twilio, SendGrid, Amazon SES, SNS, Firebase/APNs, Braze, Iterable, or OneSignal
  • Solid understanding of event-driven architectures using Kafka, Pub/Sub, Apache Beam, Kafka Streams, Flink, or similar technologies
  • Strong knowledge of message delivery semantics, including exactly-once or effectively-once processing, idempotency, deduplication, retries, and reconciliation
  • Experience designing scalable streaming pipelines with support for backpressure, dead-letter queues, replay, ordering, and fault tolerance
  • Hands-on experience building reliable provider integration layers with failover, rate limiting, webhook processing, and delivery tracking
  • Strong understanding of messaging compliance requirements, including TCPA, CAN-SPAM, 10DLC, opt-in/opt-out management, suppression lists, and sender reputation
  • Experience designing systems that protect sensitive customer data and minimize PII exposure
  • Experience building priority-based delivery architectures for high-volume messaging platforms
  • Strong understanding of scheduling and time-based delivery logic, including time zones, quiet hours, recurring schedules, and daylight saving time handling
  • Experience implementing safeguards for large-scale messaging, including approval workflows, preview mechanisms, test modes, and blast-radius protection
  • Experience designing delivery tracking, reporting, and analytics systems with accurate reconciliation across providers
  • Strong knowledge of distributed systems, scalability, reliability, and high-availability architectures
  • Excellent problem-solving skills with the ability to build highly reliable, fault-tolerant backend systems
  • Upper-Intermediate or higher level of English

WILL BE A PLUS

  • Experience with email/SMS deliverability and sender reputation management
  • Understanding of A2P 10DLC registration and messaging compliance
  • Experience with Voice & TTS solutions
  • Knowledge of template management, content rendering, and localization pipelines
  • Experience building scheduled or delayed delivery systems on cloud platforms (preferably GCP)
  • Understanding of event schema design and idempotent event modeling
  • Experience with BigQuery reporting and analytics
  • Exposure to regulated environments (e.g., FERPA/COPPA, K-12, education)

PERSONAL PROFILE

  • Strong analytical and problem-solving skills
  • Ability to work in distributed cross-functional teams
  • Proactive approach to ownership and technical decision-making
  • Strong communication and collaboration skills
  • Ability to work in high-load, fast-paced environments
  • Focus on reliability, scalability, and engineering quality
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