Senior Network Engineer in London

We are hiring a Senior Network Engineer to join a London based trading organisation operating in a highly technical, real-time environment. This is a key role within a small, specialist network team supporting event driven and low latency trading systems where network performance, resilience and availability are directly tied to business outcomes.

The organisation operates an engineering led culture with a strong focus on quality, automation and long term maintainability. Engineers are trusted to own problems end to end, influence architectural decisions and continuously improve systems that sit at the core of the trading platform. This is a hands on senior role, not a ticket driven support position. You will have real ownership over network design, evolution and performance in an environment where milliseconds matter.

The role

• You will be responsible for designing, building and evolving network infrastructure across data centres, office locations and cloud environments.
• The networks you work on underpin real time, event driven trading systems and low latency workloads, meaning careful design, rigorous testing and operational excellence are essential.
• You will play a key role in network expansion, upgrades and lifecycle management, ensuring the platform continues to scale while maintaining performance and resilience.
• A significant part of the role involves driving automation, reducing operational risk and improving observability and reliability across the network estate.
• You will work closely with trading, platform and infrastructure engineers to ensure network design aligns with system architecture and trading requirements.
• This includes capacity planning, connectivity strategy and responding to complex incidents in high availability environments.
• As part of a senior team, you will also participate in a support rota and contribute to shared ownership of the platform.

We are looking for a senior level network engineer who understands what it takes to run enterprise grade infrastructure in performance sensitive environments. You are comfortable operating under pressure, making pragmatic decisions and balancing speed with long term quality.

You enjoy working in environments where systems are real time, event driven and latency sensitive, and you naturally think about resilience, failure modes and scalability. You are a clear communicator who can explain technical trade offs to both technical and non technical stakeholders, and you value collaboration, ownership and continuous improvement.

You are also someone who enjoys staying current with networking technologies and best practices, and who sees automation as a core part of modern network engineering rather than an afterthought.

Required experience

• Strong experience designing and supporting enterprise LAN, WAN and SD WAN environments.
• Data centre networking experience, ideally including VXLAN based architectures.
• Hands on experience with Cisco and Palo Alto technologies.
• Strong understanding of core networking protocols including BGP, MPLS, multicast and TCP or UDP.
• Experience working in trading, financial services, low latency or similarly performance critical environments.
• Experience with network automation and scripting, ideally using Python.
• Infrastructure as Code experience, particularly Terraform.

Qualifications

A CCIE or CCDE qualification is desirable but not essential. Equivalent senior level experience within trading, financial services or low latency environments is equally valued.

Working model

This is a London based role with an office first working pattern, requiring four days per week on site in London. You will be part of a small specialist network team, participate in a support rota and may occasionally travel as part of the role.