System Administrator jobs in United Kingdom

Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we’re helping build a sustainable economy where everyone can prosper. We support a wide range of digital payments choices, making transactions secure, simple, smart and accessible. Our technology and innovation, partnerships and networks combine to deliver a unique set of products and services that help people, businesses and governments realize their greatest potential.

Senior Platform Engineer – Networking Overview:

We are seeking a highly skilled Senior Network Platform Engineer to join our team and play a critical role in delivering secure, resilient, and high‑performing network services across our enterprise, live, and test environments.

This is a hands‑on role, providing support to the Vocalink International business across all aspects of live, test, and disaster recovery environments.

The Senior Network Platform Engineer will be responsible for maintaining and enhancing the organization’s network infrastructure and services, ensuring high availability, performance, and security. The role also includes participation in a 24×7x365 standby rota to provide critical support when required.

• Provide 2nd and 3rd line support, build services, and consultancy to the business.
• Take ownership and accountability for all network‑related issues across the Service Delivery Life Cycle.
• Deliver effective incident management, including internal and external team communication and resolution.
• Manage and implement all approved technical changes and fault resolutions, adhering strictly to change management policies and procedures.
• Follow internal and external procedures to ensure smooth delivery of work streams and projects.
• Work independently and collaboratively, liaising with external infrastructure teams and departments to resolve complex issues.
• Define, develop, and improve procedures to enhance efficiency and benefit the wider team.
• Produce and maintain comprehensive documentation (playbooks, diagrams, Confluence entries) to ensure consistency in processes, mentoring, and repeatable practices.
• Compliance with all relevant build standards, configuration templates and audit responsibilities e.g. PCI, ISO, ISAE.
• Mentoring and training across the team to develop technical skills and capabilities.
• Commitment to continuous process improvement and a One‑Team ethos across Architecture, Build, and Run.

• Industry‑recognized accreditation (CCNP minimum, essential; Palo Alto, and F5 certifications are desirable).
• Strong knowledge of IP networks, TCP/IP technologies (DNS, SNMP etc.).
• Strong Routing, Switching and Firewall skills are essential.
• Strong knowledge of routing protocols (OSPF, BGP, EIGRP) and Layer 2/3 technologies (SVIs, STP variants, HSRP or equivalent), with practical experience across both enterprise and service provider environments.
• Proven ability to troubleshoot and resolve faults, performance issues, and configuration problems.
• Solid understanding of security and encryption technologies (PKI, SSL/TLS, IPSec, SSH, HTTPS).
• Experience in mitigating vulnerabilities (weak ciphers, expired certificates, misconfigurations, version upgrades).
• Experience in audit and risk tracking, mitigating vulnerabilities (weak ciphers, expired certificates, misconfigurations, version upgrades).
• Experience in automation and scripting, using Ansible Tower, Ansible playbooks, AS3, and Python.
• Familiarity with network management tools such as Splunk, NetBrain, SolarWinds, NNMi, Tufin, CMDB, inventory/hardware management platforms, and Wireshark.
• Atlassian experience (Jira, Confluence), and Agile frameworks (Scrum, Kanban, SAFe).
• Strong verbal and written communication skills.
• Experience in vendor management and engagement.
• Background in financial or banking environments (beneficial).
• Flexibility to travel between sites; must hold a valid driving license and own a car.
• Willingness to undergo clearance checks.
• Above all, the role requires adaptability, a commitment to continuous learning, and readiness to tackle new challenges.

• Hybrid working.
• Supports a 7 by 24 Global Network.
• May require occasional travel.

All activities involving access to Mastercard assets, information, and networks comes with an inherent risk to the organization and, therefore, it is expected that every person working for, or on behalf of, Mastercard is responsible for information security and must:

• Abide by Mastercard’s security policies and practices;
• Ensure the confidentiality and integrity of the information being accessed;
• Report any suspected information security violation or breach, and
• Complete all periodic mandatory security trainings in accordance with Mastercard’s guidelines.