Linux Engineer

iSAM is an innovative, financial technology firm specialising in quantitative trading, compromised of iSAM Funds and iSAM Securities.
iSAM Securities regulated by the FCA, SFC, and CTFC, and CIMA registered, is a leading algorithmic trading firm and trusted electronic market maker, providing liquidity, technology and prime services to institutional clients and trading venues globally. The firm offers full-service prime brokerage and execution via its cutting-edge proprietary technology, as well as market leading analytics, cleared through the group’s bank Prime Brokers.
iSAM Funds is an alternative asset manager specialising in systematic investing. Each strategy is unique, provides a specialist quantitative approach and is designed to deliver highly diversifying absolute returns for institutional portfolios.
About the Role:
We are seeking an exceptional Linux Engineer to build, operate, and continuously improve our Linux platform across latency-sensitive trading and research workloads. This is a high-impact role where your engineering choices will directly influence platform performance, reliability, and operational excellence.
You will combine deep hands-on technical expertise with an engineering mindset, taking ownership of critical systems, including Linux engineering, platform automation, storage, and GPU compute infrastructure. This role is for engineers who thrive on solving complex challenges, improving estate-wide consistency, and designing scalable platforms that enable developers and researchers to move faster with confidence.
Responsibilities
Linux platform engineering
Own and evolve the Red Hat Enterprise Linux platform lifecycle, including standardised builds, patching strategy, package management, hardening, and repeatable releases
Ensure compliance with security policies, industry standards, and best practices through automation-driven enforcement
Regularly rebuild and patch systems to mitigate security vulnerabilities
Troubleshoot and optimise data centre operations, addressing issues related to performance, hardware failures, and automation anomalies
Drive continuous improvements in system reliability, performance, and operability across the Linux estate
Automation and tooling
Implement and support automation for provisioning, configuration management, operational workflows, and self-service capabilities with tools such as Ansible, Terraform, Packer, and Python
Develop and maintain CI/CD pipelines and Docker containers to streamline infrastructure deployments
Implement Infrastructure as Code (IaC) principles to ensure consistency and scalability
Networking fundamentals
Troubleshoot complex production issues spanning host networking and application connectivity, including routing fundamentals and TCP/UDP behaviour
Partner with the network engineering team where required while retaining strong independent troubleshooting capability
Storage
Own the storage infrastructure, including architecture, operations, performance tuning, and lifecycle management
Support and evolve cutting-edge storage technologies, including:
NVMe over RoCE for ultra-low latency, high-throughput storage access
Enterprise-grade on-prem object storage
Enterprise NFS storage capabilities for shared compute and research workloads
Troubleshoot complex storage issues across hardware and software boundaries
GPU infrastructure
Own and maintain GPU-enabled Linux servers used for model training, research, and compute-intensive workloads
Operate and support the Slurm workload manager, including scheduling behaviour, node health, and operational reliability
Troubleshoot GPU stack issues across hardware and software layers, including drivers, CUDA libraries, kernel compatibility, and performance
Platform operations
Act as an escalation point for Linux production incidents, leading diagnosis and recovery under pressure
Improve system observability to identify and reduce repeat incidents
Implement safe operational processes for change management across critical systems
Core Technical Skills & Experience
Required
Extensive Linux knowledge in production environments (troubleshooting, OS internals, performance and kernel tuning)
Strong experience engineering and operating RHEL-based platforms (builds, patching, package management, hardening) including bare metal deployment (PXE, DHCP, Dell iDRAC/Redfish API)
Proven ability to automate and build operational tooling using Python, Docker, and Ansible
Fundamental understanding of core networking concepts with the ability to independently debug connectivity and performance issues
Git fluency and an engineering approach to infrastructure change (PRs, review, traceability)
Proven experience taking ownership of high impact, business-driven projects and delivering robust solutions that meet business requirements
Experience utilising Prometheus for metrics collection combined with Grafana for building dashboards, visualising system metrics and supporting operational troubleshooting
Good understanding of server architecture and hardware components (NICs, PCIe cards, SSDs, GPUs and FPGAs) and comfortable performing hands-on server work
Experience in system performance tuning balancing low latency vs throughput (NUMA optimisation and hardware/BIOS configuration)
Nice to Have
Experience in latency-sensitive environments (trading, market data, real-time systems)
Hands-on ownership of storage systems, including performance tuning and operational reliability
Familiarity with infrastructure-as-code patterns and tooling (e.g., Terraform/Packer, configuration management tooling)
Experience supporting GPU infrastructure in production (NVIDIA GPU servers, driver/toolkit lifecycle, performance monitoring)
Practical experience with Slurm or other cluster schedulers in HPC/research environments.
Exposure to performance tooling such as perf/eBPF and fundamentals like IRQ/CPU pinning/NUMA (helpful but not essential)
Operational knowledge of Kubernetes, including running and supporting containerised workloads in production environments
Understanding of time (NTP, PTP) in Linux systems, including design considerations and fault analysis
Experience working with Linux virtualisation platforms such as KVM or VMware in enterprise environments
Personal Attributes:
Clear communication – explains technical concepts concisely and effectively
Adaptability – adjusts to new technologies and unexpected challenges
Analytical thinking – breaks down complex issues logically and methodically
Decision-making – balances speed and accuracy when making technical decisions
Collaboration over competition – prioritises team success over individual wins
Accountability – follows through on commitments and owns mistakes
Patience – supports teammates as they learn or troubleshoot issues
Open to feedback – accepts and applies suggestions for improvement
Growth mindset – always looks for ways to improve skills and workflows
Proactiveness – takes initiative instead of waiting for instructions