DevOps Engineer | SDE - 1 | SDE  - 2

Role: Senior VoIP/SIP Engineer

Function: Engineering

Location: Kolkata or Gurugram

Type: Full-time

Compensation: Not specified

Industry: AI, Medical SaaS

About Company

A medical AI SaaS company building software for the U.S. dental market.

The platform helps dental teams run smoother, grow revenue, and improve patient experience. It replaces scattered tools and manual work with one integrated platform trusted by thousands of practices.

The company brings analytics, scheduling, communications, payments, and marketing automation into a single system. It automates busywork like reminders and digital intake, and gives teams real-time visibility into what's driving production and retention.

The company is mission-driven and execution-oriented with high ownership, tight collaboration, and product work with clear, measurable impact.

Position Overview

You own the design and implementation of the company's core VoIP/SIP telephony backbone that powers communication for thousands of dental practices. You architect carrier-grade SIP services and control planes using Golang and open-source components like Kamailio and FreeSWITCH. You build scalable, reliable telephony infrastructure that integrates seamlessly with the AI-powered dental practice platform, directly impacting healthcare delivery and practice efficiency.

Role & Responsibilities

• You design and implement carrier-grade SIP/VoIP core using Kamailio/OpenSIPS for signaling and FreeSWITCH for media services
• You build Golang-based SIP services including registrar, SBC components, routing logic, and monitoring daemons
• You configure SIP load balancing, failover, and high-availability setups with multi-node proxies and distributed media servers
• You implement dial plans, least-cost routing, DID management, and class-4/class-5 switching logic with carrier integrations
• You own VoIP stack security including TLS/SRTP, authentication, rate limiting, fraud detection, and abuse controls
• You integrate telephony backbone with the SaaS platform via internal APIs for user accounts, billing, and AI workflows
• You define monitoring, alerting, and capacity planning for SIP signaling, RTP/media quality, and VoIP performance metrics

Must Have Criteria

• 7-10 years software development experience with 4-5 years building large-scale VoIP/SIP systems
• Strong Golang programming skills for high-performance networked services and production APIs
• Hands-on experience with Kamailio or OpenSIPS SIP servers and FreeSWITCH or Asterisk media servers
• Deep understanding of SIP, RTP, SDP protocols, NAT traversal, and SBC concepts
• Proven experience designing highly available telephony systems with clustering and failover mechanisms
• Strong Linux and networking fundamentals including iptables, TCP/UDP, and packet-level debugging with tcpdump/wireshark
• Experience integrating VoIP platforms with REST APIs, PostgreSQL/MySQL databases, and message queues

Nice to Have

• Experience with WebRTC, SIP over WebSockets, and browser/mobile softphone integrations
• Familiarity with VoIP billing systems, rating engines, CDR processing, and class-4/class-5 softswitch products
• Cloud-native VoIP deployment experience with containerized clusters on AWS/GCP and Kubernetes
• Prior experience building call center or CPaaS platforms with programmable IVRs and analytics

What We Offer

• Opportunity to build critical telephony infrastructure for thousands of dental practices
• High ownership and autonomy in a mission-driven, execution-heavy environment
• Flexible scheduling and support for professional growth and development
• Direct impact on healthcare delivery and practice efficiency through innovative VoIP solutions
• Collaborative work with tight, cross-functional teams in Kolkata or Gurugram offices