Principal Network Engineer

Principal Network Engineer – Ultra-Low Latency | Systematic Hedge Fund | London

A leading systematic hedge fund is seeking an exceptional Principal Network Engineer to provide technical leadership across the network infrastructure underpinning its global trading and research platforms.

This is a senior individual contributor role for an engineer with deep expertise in ultra-low-latency networking and financial market infrastructure. You'll operate at the forefront of network engineering, taking ownership of the most complex technical challenges while driving architectural decisions, setting engineering standards, and shaping how critical network infrastructure is designed and operated.

The environment demands an exceptionally high level of technical capability. You'll work across latency-sensitive trading infrastructure, market connectivity, multicast, and FPGA-connected network paths, investigating performance issues that require a detailed understanding of network behaviour from the physical layer through to the trading application.

The expectation is that you'll bring the expertise and judgement to determine how complex problems should be solved, challenge existing designs where necessary, and turn architectural direction into robust, scalable engineering solutions.

The Role

• Take technical ownership of complex networking challenges across ultra-low-latency trading, market connectivity, and wider infrastructure environments
• Lead deep technical investigations into latency, packet behaviour, performance bottlenecks, resilience, and network reliability
• Act as a principal technical authority for network engineers, providing direction on complex problems and influencing critical design decisions
• Drive the evolution of network architecture, translating high-level designs into practical engineering standards, implementation patterns, and reusable solutions
• Investigate network behaviour across the full technology stack, using packet analysis, telemetry, and operational data to identify issues that require deep technical expertise
• Work across WAN, data centre, and low-latency networking, with particular emphasis on routing, multicast, and latency-sensitive market connectivity
• Analyse and optimise network paths connecting trading infrastructure and FPGA-based systems, understanding the impact of network design on overall trading performance
• Lead or contribute to complex network changes, migrations, and architectural improvements across the global estate
• Drive improvements in network automation, configuration validation, monitoring, and operational tooling to increase scalability and reduce dependency on individual engineers
• Evaluate emerging technologies and challenge existing approaches to improve performance, resilience, and supportability
• Mentor engineers and disseminate technical knowledge, raising engineering standards across the wider networking function

Requirements

• Extensive hands-on network engineering experience within a hedge fund, proprietary trading firm, exchange, high-frequency trading business, or similarly latency-sensitive financial environment
• Deep, demonstrable expertise in ultra-low-latency networking and the network architectures underpinning electronic trading
• Exceptional routing and switching knowledge, including BGP, multicast, and complex WAN and data centre environments
• Strong understanding of financial market infrastructure, including market connectivity and the networking requirements of latency-sensitive trading systems
• Experience investigating and resolving complex performance issues using packet captures, telemetry, protocol analysis, and structured troubleshooting
• Understanding of FPGA-connected network paths and the interactions between network infrastructure and trading systems
• Ability to make independent technical decisions, challenge architectural approaches, and take ownership of solutions to difficult engineering problems
• Experience translating architecture into practical engineering standards, automation, validation, and repeatable implementation patterns
• Strong understanding of network resilience, availability, and performance optimisation
• Experience with network automation, source-controlled configurations, monitoring, and operational tooling
• Proven ability to influence technical direction and mentor other engineers without relying on formal management authority

The ideal candidate will be someone others turn to when the exceptionally networking expertise is required. You should bring genuine depth in ultra-low-latency environments, a strong understanding of how financial markets operate technically, and the ability to translate that expertise into better architecture, engineering decisions, and network performance.

Company Highlights

• Technology-led culture – Drives both trading and internal engineering investment
• Significant growth across compute, storage, and networking platforms creating a strong pipeline of upcoming projects
• Opportunity to work on some of the most challenging networking problems within a large-scale HPC environment
• c.2,000 employees – large enough for scale, small enough for meaningful individual impact
• Brand-new London HQ – core engineering and trading hub with free on-site gym
• Flat organisational structure – offers meaningful ownership and direct exposure to senior technical leadership
• Highly collaborative culture with close interaction between functions facilitated by the lack of barriers between teams
• Excellent Glassdoor ratings consistently quoting a strong work-life balance
• Strong focus on innovation, automation, and engineering excellence

Strong Benefits: Free breakfast & lunch, 13% pension, year-one guaranteed bonus, allowance of work abroad days, private health, relocation packages, and more.