--- title: 'Senior Software Engineer – Core VoIP / SIP Backbone at Practice By Numbers' canonical: 'https://feeny.ai/job/senior-software-engineer-core-voip-sip-backbone-practice-by-numbers-gurugram-agrvjyds3x4v' type: 'job' last_seen: '2026-09-09' --- # Senior Software Engineer – Core VoIP / SIP Backbone at Practice By Numbers - **Company:** Practice By Numbers - **Location:** Gurugram Haryana, India - **Employment:** full-time - **Work type:** onsite - **Posted:** 2026-03-19 - **Last confirmed live:** 2026-09-09 - **Apply:** https://jobs.gem.com/practice-by-numbers/am9icG9zdDqn4UdON5TLBSN_5-6HWuRW ## Job description Senior Software Engineer – Core VoIP / SIP Backbone Practice by Numbers (PBN) | Gurugram / Kolkata, India ## About Practice by Numbers Practice by Numbers is a leading dental practice management SaaS platform serving over 1,500 dental practices across North America, providing practice management, VOIP telephony, payments, and advanced analytics. The platform is evolving into an AI‐first product, adding conversational automation and intelligent communication workflows for patients and front-office teams. ## About the Role This role owns the design and implementation of the core VoIP/SIP telephony backbone for PBN, including SIP routing, media handling, scalability, and reliability. The engineer will architect and build Golang‐based SIP services and control planes on top of open‐source components such as Kamailio (or similar SIP server), FreeSWITCH/OpenSIPS, and related media/RTP proxies. Location: Gurugram / Kolkata, India Work Mode: In-office Employment type: Full-time ## Key Responsibilities - Design and implement a carrier‐grade SIP/VoIP core using components like Kamailio/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 (multi‐node SIP proxies, distributed media servers, RTP proxies). - Implement and maintain dial plans, least‐cost routing, DID management, class‐4/class‐5 style switching logic, and integration with upstream carriers and PSTN gateways. - Own security and robustness of the VoIP stack: TLS/SRTP, authentication/authorization, rate limiting, fraud detection hooks, and abuse controls. - Integrate the telephony backbone with PBN’s SaaS platform (user accounts, billing, analytics, AI/automation flows) via well‐defined internal APIs and webhooks. - Define monitoring, alerting, logging, and capacity planning for SIP signaling, RTP/media, and VoIP quality (MOS, jitter, packet loss). - Collaborate with product and operations to translate business requirements (IVRs, call queues, routing rules, AI agents) into resilient VoIP and backend designs. Required Qualifications - 7–10 years of software development experience with at least 4–5 years building or operating large‐scale VoIP/SIP systems. - Strong Golang skills, including building high‐performance networked services, concurrent processing, and production‐grade APIs. - Hands‐on experience with at least one open‐source SIP server such as Kamailio/OpenSIPS and one media/application server such as FreeSWITCH (or Asterisk), including configuration, routing logic, and troubleshooting. - Deep understanding of SIP, RTP, SDP, NAT traversal, registrar/registrations, B2BUA vs proxy behavior, and SBC concepts. - Proven ability to design and run highly available telephony backbones: clustering, health checks, load balancing, and graceful failover. - Strong Linux and networking fundamentals (iptables, firewalls, TCP/UDP, QoS), and comfort debugging issues at packet‐level using tools like tcpdump/wireshark. - Experience integrating VoIP platforms with RESTful backends, databases (PostgreSQL or MariaDB/MySQL), and message queues for control and billing workflows. ## Nice to Have - Experience with WebRTC, SIP over WebSockets, and browser/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/FreeSWITCH clusters on AWS/GCP, Kubernetes, service meshes). - Prior work building call center or CPaaS‐style platforms, including programmable IVRs, queues, and analytics. Success Indicators - A robust, observable VoIP backbone that can sustain high call volumes with low failure rates and predictable call quality across geographies. - Rapid rollout of new telephony features (IVRs, routing rules, AI agents) through clean APIs and configuration‐driven behavior rather than manual changes. - Demonstrated reduction in telephony incidents and MTTR through automation, strong monitoring, and clear runbooks. ## About Practice By Numbers ## Company Overview - **One-liner**: Practice by Numbers is an all-in-one software platform that streamlines dental practice operations, from analytics and patient communication to payments and scheduling. - **Entity Type**: Private (no disclosed funding rounds – assumed bootstrapped or privately funded) - **Headquarters**: Redmond, Washington, United States - **Founded**: 2015 - **Founders**: Dr. Aditi Agarwal, Rohit Garg, Chris Lau ## Core Business - **Primary industry**: Dental Practice Management Software (HealthTech) - **Target customers**: Dental practices, groups, and organizations (B2B, primarily SMB and mid-market) - **Mission statement**: “Transform dental practice management through integrated software solutions that streamline operations, enhance patient experiences, and optimize business performance.” ## Products & Services - **Practice Relationship Management (PRM) Platform**: A unified suite combining analytics, patient communication, reputation management, online scheduling, online payments, patient forms, insurance verification, and more – all in one system. - **Analytics & Business Intelligence**: Dashboards and reports that give dental teams insights into practice performance, patient trends, and revenue optimization. - **VoIP / SIP Backbone**: Integrated phone system for dental practices. - **AI-Powered Tools**: AI at the core of modern dentistry to simplify operations (e.g., automation, patient engagement). ## Market Standing - **Valuation**: Not publicly available - **Key Metric**: Over 5,000 dental professionals trust the platform (2024); 400% growth since the 2022 relaunch. - **Notable Investors/Partners**: Not disclosed – key partnerships likely include dental industry networks; talent sources include Henry Schein One, Lighthouse 360, etc. - **Growth Signals**: 70 employees (+9% YoY); active job postings for senior roles (VP Sales, SRE, Product Manager); expanding presence in India and US. ## Competitive Advantages - **All-in-one integration**: Combines analytics, CRM, payments, scheduling, and phone into a single platform, reducing the need for multiple vendors. - **Dental-specific focus**: Deep domain expertise from founders (clinical + business + tech) creates a product tailored to dental workflows. - **AI-first approach**: Infusing AI into core operations to automate and optimize practice management. ## Strategic Focus - **AI & Automation**: Putting AI at the center of product development to simplify dental practice operations. - **Platform expansion**: Continuously adding modules (online booking, patient intake, payments) to become the single operating system for dental practices. - **Scaling team**: Hiring across engineering, product, sales, and customer success to support 400% growth trajectory. ## Why Work Here - **Culture**: Described as “work hard, play hard” – high energy, collaborative, with genuine friendships and celebrations. Mission-driven environment focused on improving dental care. - **Work policy**: Hybrid/remote flexibility – Bellevue, WA office; employees work remotely with hybrid options (headquarters in Redmond, also office in Evansville, IN). Remote-friendly. - **Perks**: Competitive salary, flexible schedule, professional development (training, mentorship), health coverage, wellness perks. - **Engineering culture**: Building on a modern tech stack (VoIP/SIP, AI, full-stack payments); opportunities to work on complex system challenges in a growing startup. ## Sources 1. [practicenumbers.com/company/job-listings](https://practicenumbers.com/company/job-listings/) 2. [practicenumbers.com/company/careers](https://practicenumbers.com/company/careers/) 3. [practicenumbers.com/company/about-us](https://practicenumbers.com/company/about-us/) 4. [linkedin.com/company/practice-by-numbers](https://linkedin.com/company/practice-by-numbers) 5. 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