Senior Software Developer – Mass Messaging & Notifications
Senior full-stack developer building scalable multi-channel messaging and notifications (SMS, email, voice, mobile push) for a mission-critical emergency communication platform. Day-to-day spans Node.js/GraphQL backends, Redis/MQTT queue-driven delivery, Vue/React frontends, and Docker/Kubernetes deployment, working fully remote from Latin America.
- Compensation
- Not disclosed
- Location
- São Paulo, Brazil
- Work setup
- Remote
- Seniority
- Senior
- Employment
- Full time
- Experience
- 7+ years
- Category
- Software engineering
- Posted
Skills
Must have
- 7+ years professional software development experience, incl. delivering and supporting at least one production software product
- Hands-on experience building and operating production messaging, notification, or alerting systems at scale
- Experience integrating messaging platforms such as Twilio, SendGrid, or Azure Communication Services
- Strong understanding of reliable message delivery patterns: queues, workers, retries, idempotency, deduplication, provider failover, throughput optimization
- Experience developing notification systems capable of delivering to thousands of recipients
- Knowledge of SMS compliance: opt-in/opt-out, 10DLC, toll-free registration
- Understanding of email deliverability: SPF, DKIM, DMARC, bounce handling, delivery monitoring
- Experience implementing mobile push notifications with FCM and APNs
- Experience designing data models for audiences, recipient groups, multilingual templates, and delivery tracking
- Strong backend development experience with Node.js and GraphQL APIs
- Working proficiency with Vue 3 or React
- Experience with MySQL, Redis, and message-driven or publish/subscribe systems such as MQTT
- Experience with Docker, Kubernetes, Helm, and troubleshooting containerized services
- Strong Linux and networking fundamentals: TCP/UDP, TLS, WebSockets, packet capture analysis
- Experience writing automated unit and end-to-end tests; working with GitHub Actions, Git, and pull-request workflows
- Experience using AI coding agents (e.g., Claude Code) in daily work, with ability to review and correct generated code
Nice to have
- TypeScript is a plus
Full description
WebCreek is looking for a Senior Software Developer with strong experience developing scalable messaging and notification systems to support a mission-critical emergency communication platform.
The ideal candidate has hands-on experience building and maintaining production messaging solutions that deliver notifications across multiple channels, including SMS, email, voice, and mobile push. This role requires expertise in reliable message delivery, third-party messaging integrations, asynchronous processing, and high-volume notification systems.
This position is well suited for a senior full-stack developer who enjoys solving complex distributed systems challenges, takes ownership of features from design through production, and can build reliable communication solutions that perform consistently under demanding conditions.
What You'll Do:
- Design, develop, and maintain multi-channel messaging capabilities for delivering emergency notifications through SMS, email, voice, and mobile push.
- Build and maintain integrations with messaging providers such as Twilio, SendGrid, Azure Communication Services, or similar platforms.
- Develop scalable messaging architectures using queues, background workers, asynchronous processing, and message-driven systems.
- Implement reliable delivery mechanisms, including retries with exponential backoff, idempotency, deduplication, provider failover, and delivery status tracking.
- Optimize messaging workflows to support high-volume notifications reaching thousands of recipients.
- Implement and manage delivery receipts, provider webhooks, and notification tracking processes.
- Support SMS compliance requirements, including opt-in/opt-out management, 10DLC, and toll-free registration.
- Implement email authentication and deliverability practices, including SPF, DKIM, DMARC, bounce handling, and related monitoring.
- Develop mobile push notification capabilities using Firebase Cloud Messaging (FCM) and Apple Push Notification service (APNs).
- Design data models and workflows for recipient audiences, groups, multilingual message templates, and notification delivery tracking.
- Develop and maintain backend services using Node.js, GraphQL, MySQL, Redis, and publish/subscribe technologies such as MQTT.
- Contribute to frontend development using Vue 3 or React to support notification management and operator-facing interfaces.
- Integrate with third-party mass-notification systems and support directory and roster synchronization.
- Deploy, maintain, and troubleshoot containerized applications using Docker, Kubernetes, and Helm.