Key Responsibilities :

1. Backend Development & Architecture :

- Design and develop scalable backend services using Node.js.

- Build microservices for telephony, call routing, ACD, WebRTC signaling, IVR workflows, message queues, and real-time events.

- Implement RESTful APIs, WebSocket-based services, and internal service-to-service communication.

2. Real-Time Processing (Telephony) :

- Work on telephony-related modules :

1. Call logs flow

2. ACD engine

3. WebRTC signaling

4. Real-time call events

5. Agent state transitions

6. Event-driven routing systems

- Optimize latency and concurrency for real-time voice systems.

3. Data Handling & Optimization :

- Build and optimize Elasticsearch queries (aggregation, nested, scroll, bulk, time-series handling).

- Work with MongoDB for high-volume document operations.

- Implement caching layers using Redis, TTL strategies, and pub/sub patterns.

- Handle millions of records efficiently with optimized indexing & data models.

4. Queues, Streaming & Event-Driven Architecture :

- Implement and manage high-throughput queues using RabbitMQ or Kafka.

- Build producers/consumers for telephony workflows (call events, call states, CDR processing, agent events).

5. Interprocess Communication (IPC) & System Programming :

- Implement multi-process Node.js apps (cluster mode, worker threads, child processes).

- Strong hold on OS concepts: file descriptors, sockets, event loops, buffers, concurrency models.

- Write efficient socket-based programs for internal signaling.

6. Performance, Reliability & Scalability :

- Optimize code for low latency & high throughput.

- Build retry handling, persistence queues, circuit breakers, and fail-safe mechanisms.

- Work on large-scale log processing pipelines.

7. Telephony Domain Responsibilities :

- Understand call flows, SIP/WebRTC basics (optional but preferred).

- Work on modules like call routing, IVR, call state machine, events pipeline.

- Collaborate with telephony/VoIP teams for API integrations.

8. Monitoring, Debugging & DevOps Collaboration :

- Work with DevOps for CI/CD, scaling microservices, and containerization (Docker).

Required Skills & Qualifications :

Core Technical Skills :

- Node.js (3+ years) with strong fundamentals (events, async, memory, cluster, streams).

- Elasticsearch (indexing, nested fields, aggregations, time-series queries).

- MongoDB (schema design, indexing, pipelines).

- Redis (cache, pub/sub, streams).

- RabbitMQ / Kafka (message queues, routing, consumer groups).

- WebSockets & real-time event systems.

- IPC, socket programming, networking basics.

- Excellent command over algorithms, patterns, data structures, and backend architecture.

Must-Have Knowledge Areas :

- Event-driven systems.

- API performance optimization.

- Large-scale data handling.

- Fault-tolerant distributed systems.

- High-concurrency systems.

- Memory management and Node.js internals.

- Working with large JSON data, micro-batching, and queue-based processing.