Senior MCX Core Engineer

About the role

As an MCX Senior Core Engineer, you will provide technical expertise across IMS, 4G/5G Core, MCX, VoLTE, LTE and TETRA, supporting complex deployments from design through to operations. You’ll work closely with R&D, customers and partners to deliver secure, reliable mission‑critical solutions while ensuring testing, performance and operational requirements are met.

Key responsibilities

• Provide SME support for defect triage, complex fault investigations and troubleshooting across MCX Core.
• Lead functional, performance and end‑to‑end testing, including software upgrades and regression testing on VNF/VMware Core solutions.
• Manage test progress, technical reports, trouble tickets and risks, ensuring issues are resolved within agreed SLAs.
• Support MCX Core integrations, providing technical analysis, logs and feedback to customers, partners and third parties.
• Contribute to MCX Core Test Strategies, Test Plans, documentation and the training and development of other engineers.

Required profile

• Extensive experience across 4G/5G Core, IMS, VoLTE and Mission Critical Voice, Video and Data technologies.
• Strong knowledge of LTE, TETRA, 3GPP, IP networking, routing protocols and end‑to‑end network troubleshooting.
• Experience with Wireshark, SIP, RTP, RTCP, Diameter, IXIA, Jira and ServiceNow, alongside VMware‑based Core deployments.
• Excellent analytical, technical, communication and leadership skills, with an Engineering or equivalent technical degree/experience.
• Awareness of NIST, OWASP, GCF and UK TSA requirements, with willingness to support on‑call and travel to customer locations when required.

Required skills

• 4G/5G Core
• IMS
• VoLTE
• LTE
• TETRA
• 3GPP
• IP networking
• Routing protocols
• Wireshark
• SIP
• RTP
• RTCP
• Diameter
• IXIA
• Jira
• ServiceNow
• VMware
• VNF

What we offer

• Generous holiday entitlement, plus additional birthday leave and bank holidays.
• Staff sales discount, Reward Plus shopping discount, and volunteering days.
• Government pension auto‑enrolment and pension contribution from 12 weeks.
• Subsidized staff restaurant, onsite parking, and free shuttle bus service (from Weybridge & Woking Station).