Senior strong/Lead Node.JS Engineer (#4635)

N-iX is looking for a Senior strong/Lead Node.js Engineer for one of our clients.

The first Israeli SMS aggregator - connecting businesses of all sizes to the world with an API that developers love with a live, large-scale messaging platform powering tens of millions of events daily under strict SLA requirements. We provide the backbone infrastructure that enables reliable and real-time communication at scale.

Role mission
Join the core engineering team of client, a live large-scale messaging platform, and act as a production-grade backbone engineer responsible for systems processing tens of millions of events per day under strict SLA requirements.

This is a long-term, full-time role focused on stability, scalability, and reliability, rather than feature velocity at the expense of quality. You will be expected to demonstrate enterprise-grade messaging platform knowledge, including SMS routing, delivery reports (DLRs), concurrency, provider integrations, and advanced performance optimization at scale.

Key Responsibilities:

• Design, develop, and maintain large-scale messaging and event-driven backend platforms.
• Drive migration initiatives from monolithic to microservices architectures.
• Champion low-latency, real-time system operation (WebSockets, Socket.IO, streaming pipelines).
• Ensure reliability and observability through strong monitoring and incident handling systems.
• Collaborate and integrate deeply with the engineering team to guarantee long-term platform evolution and quality.
• Take architectural ownership of critical backend flows, independently identify bottlenecks and drive solutions in high-volume transactional environments.
• Work with queue architecture (RabbitMQ / Kafka / similar) and implement best practices for rate limiting, retry logic, and failure isolation.
• Optimize APIs and database performance under high load.
• Integrate and optimize webhooks, async processing, and delivery/reporting mechanisms.

Mandatory Experience:

• Backend Engineering: 6+ years of hands-on backend experience.
• Expertise: Node.js, TypeScript at a production and expert level.
• Architecture: Microservices design and migration from monoliths.
• API Design: REST, OpenAPI / Swagger.
• High-Load Messaging: Proven experience with high-throughput systems; message queues/event-driven (Kafka or RabbitMQ mandatory).
• Resilience: Handling backpressure, retries, DLQs, idempotency, rate limiting, failure isolation.
• Realtime Systems: Experience with realtime systems (WebSockets, Socket.IO, WebRTC, streaming pipelines), processing telemetry or delivery reports.
• Databases & Caching: PostgreSQL/MySQL (schema design, performance tuning), Redis for caching/buffering.
• Cloud & Deployment: Strong experience with GCP, Docker, CI/CD pipelines.
• Observability: Prometheus, Grafana, Datadog, Sentry, or Kibana.
• Production Readiness: Experience in incident response and on-call rotations.
• Experience with SMS routing, delivery reports (DLRs), and integrating multiple messaging providers is highly preferred.
• Demonstrated capability to optimize systems for scalability, monitoring, and bottleneck analysis.

Strong Advantages (Nice to Have):

• Payments, fintech, or banking system experience.
• Security and authentication (JWT, OAuth2).
• Infrastructure as Code (Terraform).
• Kafka at scale.
• Technical leadership, system ownership roles.
• Experience with unstable third-party APIs.