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Role: Senior Software Engineer – VoIP / SIP Function: Software Engineering / Telephony Infrastructure Location: Kolkata / Gurugram Type: Full-time Industry: AI, Medical SaaS, Dental Medical SaaS About Company The company builds medical AI SaaS for the U.S. dental market. Thousands of dental practices across North America rely on its platform daily. It unifies analytics, scheduling, communications, payments, and marketing automation into one system. The platform automates admin work and gives teams real-time visibility into revenue and retention. Founded in 2015 by a practicing dentist, a data strategist, and a PhD technologist. The company is mission-driven, execution-oriented, and moving fast in a large, under-digitized healthcare vertical. Position Overview This role owns the design and implementation of the company's core VoIP/SIP telephony backbone — the infrastructure layer that powers calling, routing, and communication workflows for thousands of dental practices. The engineer will architect and build carrier-grade SIP services in Golang on top of open-source components, and integrate the telephony stack with the company's broader AI-first SaaS platform. The role reports to the Engineering India Head and sits at the intersection of deep infrastructure work and product-facing impact. Role & Responsibilities Design and implement a carrier-grade SIP/VoIP core using Kamailio or OpenSIPS for SIP signaling and FreeSWITCH or similar for media and application services. Build Golang-based SIP services — registrar, SBC-like components, routing logic, monitoring daemons — and internal APIs to control routing, policies, and provisioning. Configure and operate SIP load balancing, failover, and high-availability setups across multi-node SIP proxies, distributed media servers, and RTP proxies. Implement and maintain dial plans, least-cost routing, DID management, class-4/class-5 switching logic, and integrations with upstream carriers and PSTN gateways. Own security and robustness of the VoIP stack: TLS/SRTP, authentication, rate limiting, fraud detection hooks, and abuse controls. Integrate the telephony backbone with the company's SaaS platform via well-defined internal APIs and webhooks, covering user accounts, billing, analytics, and AI/automation flows. Define and own monitoring, alerting, logging, and capacity planning for SIP signaling, RTP/media, and VoIP quality metrics (MOS, jitter, packet loss). Must Have Criteria 7–10 years of software development experience with at least 4–5 years building or operating large-scale VoIP/SIP systems in production. Strong Golang skills including high-performance networked services, concurrent processing, and production-grade APIs. Hands-on experience with at least one open-source SIP server — Kamailio, OpenSIPS, or Asterisk — including configuration, routing logic, and packet-level troubleshooting. Deep understanding of SIP, RTP, SDP, NAT traversal, registrar/registration flows, B2BUA vs. proxy behavior, and SBC concepts. Proven ability to design and operate highly available telephony backbones: clustering, health checks, load balancing, and graceful failover. Strong Linux and networking fundamentals — iptables, firewalls, TCP/UDP, QoS — with comfort debugging at packet level using tcpdump or Wireshark. Experience integrating VoIP platforms with RESTful backends and databases (PostgreSQL or MariaDB/MySQL) and message queues for control and billing workflows. Nice to Have Experience with WebRTC, SIP over WebSockets, and browser or mobile softphone integrations. Familiarity with VoIP billing, rating engines, CDR processing, and reseller hierarchies (class-4/class-5 softswitch products or similar). Cloud-native deployment of VoIP stacks — containerized Kamailio or FreeSWITCH clusters on AWS or GCP, Kubernetes, service meshes. Prior work building call center or CPaaS-style platforms including programmable IVRs, call queues, and analytics. What We Offer End-to-end ownership of a mission-critical infrastructure layer powering thousands of live dental practices across North America. Direct exposure to AI-first product evolution — conversational automation, intelligent call routing, and front-office workflow integration. High-autonomy environment with tight cross-functional collaboration across product, engineering, and operations. Flexible scheduling within a fast-moving, execution-oriented team with real, measurable impact.
Here's how to pick the right one and stand out in your application.
144.883Jobs
31.687IN
81%EN
That number is real. WorkMundi's database shows 144,883 open engineer roles across the world. India has the most with 31,687 jobs, followed by the United States with 30,084. If you just finished reading one job ad and felt paralyzed by choice, you're not alone—but this scale is actually an advantage. It means you can afford to be selective.
Start by geography and language. The majority of engineer ads—117,837 of them—have the job posting text written in English. Use that as one filter, but remember: the ad text language tells you nothing about whether the role actually requires you to speak English day-to-day. Read the job description carefully. Then check which countries have the volume you're targeting. Singapore, Poland, and Australia round out the top five after India and the US.
Next, learn who's hiring. Accenture has posted 2,801 engineer roles. andurilindustries, speechify, and jobgether are also actively recruiting. If you're applying to one of these names, research their hiring patterns and interview style before you apply. That homework pays off.
When you interview, expect the question every engineer hears: 'Tell me about a time you had to debug a problem that wasn't in your job description.' Have a specific story ready—not a general one. Name the tools, the deadline pressure, and what you learned. Hiring managers listen for whether you see problem-solving as part of the role itself, not a favour.