MERN Stack Developer

About the Role
We are hiring a highly skilled Senior Backend Node.js Developer who can build, optimize, and scale the backend infrastructure of Sarv’s Deepcall — a high-performance cloud telephony & omnichannel communication platform.
This role needs someone with deep backend fundamentals, experience with high-volume systems, real-time events, distributed queues, microservices, and data streaming.
You will be working with Node.js, Elasticsearch, MongoDB, Redis, RabbitMQ/Kafka, WebSockets, IPC, and custom telephony modules.

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:
   ○ Call logs flow
   ○ ACD engine
   ○ WebRTC signaling
   ○ Real-time call events
   ○ Agent state transitions
   ○ 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.

Good to Have / Preferred
● Experience with Telephony: SIP, RTP, WebRTC signaling, Asterisk/Freeswitch basics.
● Knowledge of microservices architecture & containerization (Docker).
● Experience in building SaaS or CPaaS platforms.
● Exposure to distributed locks, rate-limiting, throttling strategies.

Soft Skills
● Strong ownership & accountability.
● Ability to break complex problems into clean, modular solutions.
● Clear communication and ability to work with product, QA, telephony & infra teams.
● Debugging mindset—can trace issues across distributed systems.