Walk-in | UCaaS Software Developer - FreeSWITCH, Asterisk, SIP, WebRTC

Swadesh Mobile; Mumbai; On-site; INR 1,200,000 - 1,900,000; Full time

Job summary

Swadesh Mobile is seeking an experienced VoIP / UCaaS Developer to design, develop, integrate, and maintain scalable Unified Communications as a Service (UCaaS) and real-time communication solutions.

The ideal candidate will have hands-on experience with FreeSWITCH, Asterisk, SIP, RTP, WebRTC, Kamailio/OpenSIPS, PJSIP, SBCs, and SIP trunking, along with Python and/or Node.js programming expertise. Strong Linux and networking knowledge are essential.

Qualifications

• Experience with FreeSWITCH and/or Asterisk in production environments.
• Strong knowledge of SIP, RTP, SDP, and VoIP protocols.
• Hands-on WebRTC and real-time communications experience.
• Experience with Kamailio and/or OpenSIPS.
• Proficiency in Python and/or Node.js.
• Strong Linux systems and networking knowledge.
• Experience with SIP call routing and signaling troubleshooting.
• Ability to design scalable VoIP/UCaaS platforms.

Responsibilities

• Design, develop, and maintain scalable VoIP and UCaaS solutions.
• Develop and customize telephony applications using FreeSWITCH and Asterisk.
• Implement and troubleshoot SIP, RTP, SDP, WebRTC, and PJSIP technologies.
• Configure and manage SIP routing using Kamailio and OpenSIPS.
• Develop and integrate SBC, softswitch, and SIP trunking solutions.
• Build backend services, APIs, and automation using Python and Node.js.
• Develop and integrate WebRTC-based real-time communication solutions.
• Design call flows, SIP routing, failover, load balancing, and high-availability architectures.
• Troubleshoot SIP signaling, NAT, and interoperability issues.

Skills

FreeSWITCH

Asterisk

SIP

RTP

WebRTC

Kamailio

OpenSIPS

PJSIP

SBCs

Softswitches

Python

Node.js

Linux

Networking

VoIP security

Job description

Job Title: UCaaS / VoIP Software Developer

Role: UCaaS Software Developer

Specialization: VoIP, Unified Communications, SIP, WebRTC, Real-Time Communications

Job Summary:

We are seeking an experienced VoIP / UCaaS Developer to design, develop, integrate, and maintain scalable Unified Communications as a Service (UCaaS) and real-time communication solutions.

The ideal candidate will have strong hands-on experience with FreeSWITCH, Asterisk, SIP, RTP, WebRTC, Kamailio, OpenSIPS, PJSIP, SBCs, and SIP Trunking, along with programming expertise in Python and/or Node.js. Strong knowledge of Linux, VoIP architecture, SIP signaling, call routing, and real-time communication systems is essential.

Key Responsibilities

• Design, develop, and maintain scalable VoIP and UCaaS solutions.
• Develop and customize telephony applications using FreeSWITCH and Asterisk.
• Implement and troubleshoot SIP, RTP, SDP, WebRTC, and PJSIP technologies.
• Configure and manage SIP routing using Kamailio and OpenSIPS.
• Develop and integrate SBC, softswitch, and SIP trunking solutions.
• Build backend services, APIs, and automation using Python and Node.js.
• Develop and integrate WebRTC-based real-time communication solutions.
• Design call flows, SIP routing, failover, load balancing, and high-availability architectures.
• Troubleshoot SIP signaling, RTP/media, call quality, registration, NAT, and interoperability issues.
• Integrate SIP trunks, telecom carriers, third-party APIs, and communication platforms.
• Deploy, configure, and optimize Linux-based VoIP infrastructure.
• Monitor system performance, reliability, scalability, and security.
• Collaborate with engineering and product teams to deliver new UCaaS and VoIP features.

Required Skills:

• Strong hands-on experience with FreeSWITCH and/or Asterisk.
• Strong understanding of SIP, RTP, SDP, and VoIP protocols.
• Practical experience with WebRTC and real-time communications.
• Experience with Kamailio and/or OpenSIPS.
• Knowledge of PJSIP, SIP Trunking, SBCs, and Softswitches.
• Proficiency in Python and/or Node.js.
• Strong knowledge of Linux systems and networking.
• Experience with SIP call routing, signaling, media flows, and troubleshooting.
• Understanding of NAT, firewalls, codecs, SIP registration, and VoIP security.
• Experience building or maintaining scalable and reliable VoIP/UCaaS platforms.

Preferred candidate profile

• Experience in UCaaS, CPaaS, cloud telephony, or real-time communication platforms.
• Experience with SIP proxy, registrar, and routing architectures.
• Knowledge of VoIP monitoring, logging, and troubleshooting tools.
• Experience with REST APIs and third-party communication integrations.
• Familiarity with cloud platforms, containers, and distributed systems.
• Understanding of high-availability and carrier-grade VoIP architectures.

Ideal Candidate:

We are looking for a technically strong VoIP / UCaaS Developer with practical experience in building and supporting real-time communication platforms. The candidate should have a strong understanding of telephony protocols, SIP infrastructure, media handling, VoIP development, and Linux-based systems, with the ability to develop scalable and reliable UCaaS solutions.