Senior Network Security Engineer - Design, Deploy & Secure

Janestreet; Greater London; On-site; GBP 120,000 - 180,000; Full time

Job summary

Jane Street in London is seeking an experienced Network Engineer for the Network Security team to run, scale, and improve our security infrastructure through hands-on operations, design, and implementation. The role emphasizes advanced networking, security appliances, and cross‑firm collaboration to deploy secure workflows and enhance observability.

The ideal candidate has 7+ years’ experience, expertise in routing protocols (OSPF/BGP/PIM-SM), firewall architecture and configuration, PKI,

Qualifications

• 7+ years of experience operating and deploying network infrastructure.
• Experience with routing and network protocols (OSPF, BGP, PIM-SM).
• Experience troubleshooting transport protocols (TCP/UDP).
• Strong understanding of firewall hardware architecture, performance metrics, and its functional components.
• Experience with firewall configuration and troubleshooting.
• Understanding of Public Key Infrastructure and related technologies.
• Understanding of modern encryption techniques.
• High capacity to learn; we are interested in how you think, not just what you know.
• Ability to context switch, while still being able to prioritize and organize your stack.
• Ideally experience with overlay networks (EVPN, VXLAN).
• A flexible and reliable team player who enjoys working in a collaborative environment.
• Proficiency in a programming language is preferred.
• Fluency in English is required.

Responsibilities

• Work closely with Network Engineering on design and deployment of security perimeter and adjacent network infrastructure.
• Effectively manage and continuously evolve network segmentation, DMZ, and other aspects of network security.
• Evaluate and lab test new platforms for our network security infrastructure.
• Collaborate with Cybersecurity on detection and mitigation of threats and vulnerabilities on our network.
• Interface with application owners and traders to enable business workflows in a secure way.
• Proactively enhance support by improving network infrastructure observability, scripting, and communicating requirements to our software engineers.
• Improve our network security processes and documentation.

Skills

Network infrastructure

OSPF/BGP/PIM-SM

TCP/UDP

Firewall architectures

Firewall configuration

PKI

Encryption techniques

Learning ability

Context switching

EVPN

VXLAN

Team player

Programming language

English fluency

Tools

EVPN

VXLAN

Job description

Jane Street in London is seeking an experienced Network Engineer for the Network Security team to run, scale, and improve our security infrastructure through hands-on operations, design, and implementation. The role emphasizes advanced networking, security appliances, and cross‑firm collaboration to deploy secure workflows and enhance observability.

The ideal candidate has 7+ years’ experience, expertise in routing protocols (OSPF/BGP/PIM-SM), firewall architecture and configuration, PKI,