Senior Telecom Engineer

About the role

Five9 is seeking a Senior Telecom Engineer to join its Cloud Operations team. The role supports a global cloud contact‑center platform and works 24/7 to ensure voice services run smoothly for customers worldwide. The position can be based anywhere in the UK and operates on a full‑time basis.

Key responsibilities

• Interface with customers' telecom engineers and IT teams to deploy customized solutions and troubleshoot issues.
• Provide day‑to‑day operational support of the telecommunications network, analysing problems affecting availability and quality.
• Act as escalation point for the Network Operations Center to resolve critical SBC alerts.
• Analyse incident history and implement preventive measures.
• Deliver root‑cause analysis for service outages and coordinate corrective actions.
• Create technical documentation and call‑flow diagrams.
• Manage relationships with telecom service providers and vendors.
• Deploy hardware and software updates, new services and conduct inter‑op testing with carriers.
• Provide emergency assistance and participate in on‑call rotation.

Required profile

• 3‑5 years of experience as a telecom engineer in a 24/7 production support environment.
• Strong working knowledge of VoIP, SIP and RTP technologies.
• Experience with session border controllers (e.g., Ribbon SBCs, PSX) and voice codecs.
• Familiarity with international routing, DIDs, toll‑free numbers and related terminology.
• Ability to build, interoperate and maintain direct‑connect SIP trunks to customers and carriers.
• Comfortable working remotely and collaborating with global teams.

Required skills

• VoIP, SIP, RTP
• Session Border Controllers (Ribbon SBCs, PSX)
• H.248, G.711, G.729, WebRTC codecs
• TCP/IP, UDP, MPLS, VPN
• TLS, IPSEC, ACLs
• Least Cost Routing, SIP call routing
• DIDs, Toll‑Free numbers, LATA, OCN, NPA‑NXX
• ITFS, iDID, international routing policies
• SIP trunk provisioning and inter‑op testing