Salary: £55,000 - 65,000 per year Requirements: 3-5 years experience of development in an SIP/VOIP environment, using Python or a similar object-oriented language Experience with Flask/Django, Jinja, Pytest, SQLAlchemy, Marshmallow Proficient in Wireshark for SIP/RTP trace analysis and fault-finding Knowledge of Docker containerisation Experience with Linux (Ubuntu) based systems Knowledge of Freeswitch, C/C++, Kamailio, Auth0/0Auth, Mongo DB, My SQL, ArgoCD/Kubernetes or Web RTC is advantageous Responsibilities: 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 Analyzing SIP/RTP traces to troubleshoot issues Technologies: AI ArgoCD Backend CI/CD Django Docker Flask Kubernetes Linux Python REST SQL Security Ubuntu Web pytest More: We are delighted to partner with an established market leader in managed communications technology and systems integration, who has been at the forefront of innovation for over 40 years. Our company transforms customer experiences through smarter communications, automation, analytics, and AI, delivering transformative communication and CX solutions across the UK and internationally. We are looking for a Software Engineer to join our small Software Development Team, working on our enterprise-level SIP platform and its associated REST APIs. This permanent role offers a generous benefits package, including retail discounts, private healthcare, flexible working arrangements, and excellent career development opportunities in a people-first environment. last updated 5 week of 2026