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. 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