Network Security Engineer

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

About the Position

We are looking for an experienced Network Engineer to join our Network Security team to help us to run, scale and continuously improve our network security infrastructure through hands-on operations, design, and implementation. The ideal candidate would have strong networking fundamentals and experience with security appliances such as firewalls and proxy to join our Network Security team.

Jane Street’s numerous distributed systems are built on an agile, reliable, multi-vendor network infrastructure that supports all traffic profiles, from trading to internet connectivity. Supporting such a large multi-function network requires advanced tooling for monitoring and automation.

Strong communication and interpersonal skills will be needed to collaborate with colleagues across the firm globally. You will find and resolve issues, plan and execute deployments, and improve systems where possible. In this role, we’ll look to leverage your advanced networking skills and security knowledge to:

• 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

A holistic approach to system design is critical for this role. The Networking department prioritizes flexibility, compatibility, and efficiency when crafting solutions, all while seeking ongoing buy-in and feedback from users across the firm. Our firm’s culture prizes intellectual humility, openness, and continuous improvement, which translates directly to the daily work of this team. We’re all partners working towards shared goals and are always looking for the next best idea that will make our work stronger.

Your strong communication skills and analytical thinking will be invaluable as we support the daily work of our colleagues and keep our systems operating at the highest standard.

About You

• 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