Experienced Developer (SIP/VoIP)

Mobilus Limited; England; On-site; GBP 45,000 - 60,000; Full time

Job summary

A leading technology company in the UK is seeking a Software Engineer to join their Software Development Team. The ideal candidate will have 3-5 years of experience in SIP/VOIP development, with strong skills in Python, Flask, and Docker. Responsibilities include designing backend features and maintaining integrations with AI voice services. The role offers a generous benefits package, including flexible working arrangements and private healthcare. This is an excellent opportunity for those looking to grow their career in a company with a proven track record.

Benefits

Retail discounts

Private healthcare

Flexible working arrangements

Qualifications

• 3-5 years experience in an SIP/VOIP environment.
• Knowledge of Docker containerization.
• Experience with Linux (Ubuntu) systems.

Responsibilities

• Design and deliver backend features.
• Build and maintain integrations with AI-driven voice services.
• Conduct code reviews and troubleshoot SIP/RTP issues.

Skills

Python

SIP/VOIP development

Flask/Django

Wireshark

Docker

Linux (Ubuntu)

Tools

SQLAlchemy

Marshmallow

Pytest

Job description

Overview

We are delighted to be working in partnership with an established market leader in managed communications technology and systems integration who develop their own products. For over 40 years, they ve been at the forefront of innovation, transforming customer experiences through smarter communications, automation, analytics and AI. They deliver transformative communication and CX solutions throughout the UK and internationally, supporting clients with global reach and ambition. As the business expands, they are looking to onboard a Software Engineer to join a small Software Development Team, as they expand and extend their enterprise-level SIP platform and its associated REST APIs.

Responsibilities

• The developer will be responsible for:
• Designing and delivering backend features
• Building and maintaining integrations with AI-driven voice services
• Turning requirements into clear technical designs and high-quality code
• Improving CI/CD and observability, hardening security by design, conducting code reviews and analysing SIP/RTP traces to troubleshoot issues

Essential Skills

• 3-5 years experience of development in an SIP/VOIP environment, using Python or a similar object-oriented language
• Flask/Django, Jinja, Pytest, SQLAlchemy, Marshmallow
• Wireshark for SIP/RTP trace analysis/fault-finding
• Docker containerisation
• Linux (Ubuntu) based systems

Any knowledge of Freeswitch, C/C++, Kamailio, Auth0/0Auth, Mongo DB, My SQL, ArgoCD/Kubernetes or Web RTC would prove advantageous for this role.

This is a fantastic and exciting opportunity for an experienced Developer to work as part of a people-first company that holds exceptional staff retention rates and career development opportunities. The role comes with a generous benefits package, including retail discounts, private healthcare, flexible working arrangements and many more. If you re ambitious, curious and can demonstrate loyalty as an employee, this is your chance to learn and grow your career in a company with pedigree, purpose and potential.

Please note that this is a permanent role seeking candidates with a track record of longevity of service with their previous employers.