Telephone or VOIP Engineer

KBC Technologies Group; Greater London; On-site; GBP 60,000 - 80,000; Full time

Job summary

A telecommunications technology firm based in Greater London is seeking a Senior Engineer with deep experience in telephony solutions. This hands-on role requires expertise in C/C++ programming for VoIP systems, solid understanding of SIP protocol, and familiarity with public cloud environments like AWS or Azure. Candidates should be comfortable with Linux administration and have experience working with open-source software such as Asterisk and Freeswitch. The position involves designing and maintaining telecommunication services, requiring strong problem-solving skills and collaboration across teams.

Qualifications

• Deep expertise and experience in telephony/voice software engineering.
• Significant experience with SIP protocol, signalling, and analysis.
• Comfortable with automated environments and Infrastructure as Code.

Responsibilities

• Design, ship and maintain telecommunication services.
• Support production systems and collaborate across teams.
• Solve complex problems in audio-related systems.

Skills

Telephony programming

Agile software development

C/C++ programming for VoIP

SIP protocol knowledge

Network routing and NAT

Linux administration

Open-source software experience

Container platforms (Docker, Kubernetes)

Tools

AWS

Azure

GCP

Terraform

SIPp

Asterisk

Freeswitch

OpenSIPs

Job description

We’re looking for a Senior Engineer with deep telephony experience . You’ll be part of a distributed team, modernising and maintaining capture platforms and tools in a multi-cloud environment across many geographies. If you like solving complex problems in simple ways and have a passion for all things audio, then this might be the role for you.

This is a hands‑on engineering role with significant ownership: you’ll design, ship and maintain telecommunication services, support production systems, and collaborate across engineering, product, and customer‑facing teams to deliver robust solutions.

About You

You’re enthusiastic, and like solving problems and being hands

You enjoy communicating and collaborating with

You’re curious, eager to learn, and have a desire to continuously improve your

You have previous experience in agile software

You got deep expertise and experience in software engineering of telephony/voice solutions

You’ve (ideally) worked in public cloud environments (AWS, Azure, GCP or other).

You’ve got some knowledge of Docker and Kubernetes (or similar container platforms).

You’re familiar with highly‑automated environments deployed through Infrastructure as Code (using Terraform or similar).

You know about coding and security best practices and relevant

You’re comfortable supporting what you

You’re experienced in programming in C/C++ (oriented to VoIP software).

You have significant experience in SIP protocol including signalling and

You have experience with SIP signalling analysis for SIP Proxy, SBC, Gateway, Trunk, Registration and bridged media sessions.

You have experience with open‑source software like Asterisk and Freeswitch (configuration, compilation and installation of modules).

You have experience with OpenSIPs (Load balancing, branches and routes).

You’re confident with Linux administration (command line) for updating, patching, compiling and creating deb packages.

You have knowledge of telephony codecs and media containers such as PCMU, PCMA, WAV and

You have experience Generating SIP scenarios for functional and load testing (SIPp and/or other tools).

You’re strong in IP networking and have knowledge of routing, NAT, DNS, VPNs and firewalls.

You have SBC knowledge with AudioCodes, Oracle/Acme Packet or