Senior Network Specialist

twentyAI; Greater London; On-site; GBP 60,000 - 80,000; Full time

Job summary

A leading company in the tech sector is seeking a Team Lead for Core IT, Infrastructure & Security. This role involves designing and maintaining complex network systems, ensuring high performance in low-latency environments. The ideal candidate will have extensive experience in multicast technologies and security, contributing to the organization's infrastructure strategy and continuous improvement efforts.

Qualifications

• Proven experience in enterprise-scale networks, especially in finance/trading.
• Hands-on experience with multicast networking and security platforms.

Responsibilities

• Design and maintain complex network systems to meet business demands.
• Lead network upgrades and manage enterprise firewall environments.

Skills

Low-latency Networking

Multicast Technologies

Network Troubleshooting

Firewall Administration

Tools

F5 BIG-IP

Palo Alto

Cisco ASA

CheckPoint

Job description

Direct message the job poster from twentyAI

Team Lead - Core IT, Infrastructure & Security

We are seeking an Expert Data Center & Security Engineer with extensive expertise in low-latency networking, multicast technologies, and secure data center infrastructure. This is a hands-on, high-impact engineering role responsible for the full lifecycle of network systems—from design and deployment to performance monitoring and continuous improvement.

Key Responsibilities

• Design, build, and maintain complex network systems and applications to meet evolving business and technical demands.
• Translate business requirements and performance data into robust technical solutions aligned with capacity and infrastructure strategies.
• Develop real-time dashboards and monitoring systems to visualize network health and performance.
• Provide expert support for multicast and WAN implementations, acting as the primary escalation point for complex issues.
• Lead network upgrades and migrations, coordinating with internal teams and third-party providers.
• Manage enterprise firewall environments and contribute to secure network architecture reviews.
• Maintain thorough documentation and conduct detailed system performance reviews to drive continuous improvement.
• Contribute to engineering patterns, enabling automation, testing, and deployment of network solutions within an SRE/DevOps framework.

Technical Requirements

• Proven experience working on enterprise-scale networks, particularly in latency-sensitive environments (finance/trading preferred).
• Deep knowledge of LAN, WAN, HSRP, NAT, MPLS, VPN, GRE, BGP, and OSPF protocols.
• Advanced expertise in multicast networking: PIM-SM, PIM-SSM, IGMP, MVPN, MLDP.
• Hands-on experience with F5 BIG-IP (LTM, GTM, etc.).
• Strong background in firewall administration and security: Palo Alto, Cisco ASA, CheckPoint, or similar platforms.
• Proficient with network packet analysis and troubleshooting using packet capture tools.
• Experience with Data Centre and SDN technologies: Cisco ACI, VxLAN, and related tooling.
• Understanding of network automation principles; exposure to SRE/DevOps practices is a plus.
• Working knowledge of TCP/IP and multicast in internet-facing architectures.

Seniority level

• Mid-Senior level

Employment type

• Full-time

Job function

• Information Technology

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