Principal Back End Developer

We are building a high-scale consumer mobile app. We need a hands-on Technical Lead to own the "seam" between our Mobile Apps (iOS/Android) and Backend (Node.js/Socket.IO). The Lead will manage the integration of software systems, troubleshoot issues, and coordinate with relevant teams to ensure seamless functionality. the role requires the candidate to Own API/socket contracts, SLO/observability gates, and cross-team Integration and delivery across

Android, iOS, Node, and FastAPI/ML, i.e., Node.js Expert + Socket.IO + Mobile Networking , We need a

hands-on integration engineer

who owns the seams between

mobile ↔ API ↔ async workers , prevents duplicate jobs, enforces versioned contracts, and sets up production-grade observability. This is NOT a Manager/PM role. This is NOT an SAP/Enterprise Middleware role. This is a hands-on role. If you do not code Node.js daily, please do not apply.This role involves collaborating with stakeholders, analyzing system requirements, and ensuring solutions align with project objectives and timelines.

Mandatory Tech Stack (Non-Negotiable): Language: Node.js (Expert), Python (Intermediate) Mobile: Deep understanding of iOS/Android networking (you don't need to write Swift, but you must know how URLSession works). Real-Time: Socket.IO / WebSockets (Production experience required).

Other Qualifications: Strong Analytical Skills to evaluate and resolve complex system challenges Write/own OpenAPI+Socket ICDs; versioning & deprecation. Implement/guide idempotent POSTs, retry/DLQ, admission control. Ensure trace propagation app → edge → queue → worker; build dashboards. Coordinate Android/iOS parity and model rollout headers/versioning. Effective Communication skills for cross-functional team collaboration Knowledge of Software Development processes and tools Experience with Ship-quality code in Node.js/TypeScript or Python for APIs/workers. Production experience with queues (RabbitMQ/Kafka), Socket.IO/WebSockets. Experience with OpenTelemetry tracing + Prometheus/Grafana dashboards.