Principal PBX & VoIP Infrastructure Engineer (Build the whole infrastructure)

We are looking for a highly experienced **PBX/VoIP Infrastructure Engineer** to lead the design and development of our **in\-house PBX system from A to Z**. This person will own the entire telecommunications infrastructure, including architecture, PBX platform, SIP, networking, servers, security, redundancy, integrations, deployment, monitoring, and ongoing operations. Responsibilities * Design and build our complete in\-house PBX/VoIP infrastructure. * Configure and manage SIP trunks, DIDs, extensions, IVR, call queues, routing, voicemail, and call recording. * Design the supporting network, servers, firewalls, SBCs, and QoS. * Implement security, redundancy, backups, monitoring, and disaster recovery. * Integrate the PBX with CRM, applications, APIs, and other business systems. * Troubleshoot complex SIP, RTP, networking, and call\-quality issues. * Automate provisioning and operational tasks. * Fully document the architecture and systems. Requirements * **8\+ years of hands\-on PBX/VoIP experience.** * Proven experience **building PBX systems from the ground up**. * Strong knowledge of **SIP, RTP, VoIP, networking, Linux, and firewalls**. * Experience with **Asterisk, FreePBX, FreeSWITCH, Kamailio, 3CX, or similar platforms**. * Experience with SIP carriers, SBCs, high availability, security, and disaster recovery. * Strong troubleshooting and scripting/automation skills. * Ability to independently take a project from **architecture → build → deployment → production**. Ideal Candidate We need a **builder and technical owner**, not simply a PBX administrator. You should be capable of taking a blank environment and designing, building, securing, deploying, and operating a production\-grade PBX infrastructure from start to finish. Pay: $97,300\.00 \- $118,000\.00 per year Application Question(s): * Can you take us from point A to Z building an in house PBX system \& build the whole infrastructure? Work Location: In person