MXC Engineer

This role sits within the Mission Critical Test and Certification team of a leading global tech company’s Networks Europe division. The team is driving entry into the Public Services domain across Europe, delivering a market-leading portfolio that spans Device Clients, RAN, Core, and Mission Critical Application Services.

This role requires 3 days per week onsite in Berkshire office, 2 days per week remote.

As an MCX Engineer, you will work across the Test and Delivery teams under the guidance of Test and Service Delivery Managers. You’ll play a pivotal role in ensuring the performance, reliability, and availability of our solutions—meeting customer expectations, contractual milestones, and service level agreements (SLAs).

Joining our team means becoming part of a group of highly skilled technical specialists who define and deliver industry-leading MCX solutions, supported by strong collaboration with colleagues across Europe and at our global headquarters.

Key Responsibilities

• Act as a technical expert in IMS (and ideally MCX), applying analytical skills to troubleshooting, root cause analysis, and end-to-end testing.


• Provide solution expertise and guidance for MCX Client and Application Test Strategy and Test Plans across network elements and software releases.


• Execute Functional, Performance, Accessibility, and Compatibility test plans.


• Track and report test progress accurately within defined project timelines.


• Validate test cases, upgrade procedures, troubleshooting guides, and documentation to ensure consistent and reliable test execution.


• Conduct detailed analytics and fault investigations to resolve feature and performance issues within SLAs.


• Provide continuous feedback and recommendations on training and development for yourself and fellow engineers.


• Execute MCX Client porting and verification testing to support R&D in meeting release criteria.


• Produce detailed test progress reports and performance logs.


• Manage trouble tickets through to resolution, ensuring comprehensive documentation for R&D investigation and implementation of recommendations.


• Offer technical support during Sandbox testing, providing analysis, feedback, and logs to third parties for solution development or integration.

What We’re Looking For

• Strong background in 4G/5G Core technologies, particularly Voice, Video, and Data services for users and applications.


• Deep expertise with MCX Client applications and SDK solutions on Android (GMS, non-GMS, Android Go), iOS, Linux, and Windows OS.


• Proficiency with LTE testing tools (Wireshark, IXIA, Viavi, Spirent, XCAL, XCAP, QXDM, Jira, HPQC, Logcat/Putty); experience with MCPTT QCIs is a plus.


• Experience in software lifecycle testing for VNF deployments on VMware.


• Knowledge of client software deployment methods via OTA and EMM.


• Proven ability to perform end-to-end troubleshooting for LTE and TETRA networks and call flows.


• Strong understanding of 3GPP specifications and Mission Critical features.


• Excellent presentation, communication, and interpersonal skills in written and spoken English.


• Engineering degree (or equivalent experience) in Computer Science, Electronics, Telecommunications, or a related field.


• Familiarity with GCF and other testing standards for client certification.


• Flexibility to support on-call rotations as needed.


• Willingness to work on-site with customers for extended project support periods.

What Success Looks Like

• A self-motivated, driven professional who thrives as part of a small team of test experts.


• Ability to execute complex testing activities to defined project and test milestones.


• Collaborative approach, working with PMO functions to report progress and address project risks effectively.


• Strong and lasting working relationships with customers and partners.


• Acts as the subject matter expert for deep technical investigations across end-to-end LTE and TETRA architectures.


• Flexibility and reliability to support on-call duties and customer site engagements as required.