L4 Network Engineer

Claranet; City Of London; On-site; GBP 75,000 - 120,000; Full time

Job summary

Claranet is seeking an L4 Network Specialist to provide technical leadership, architectural governance, and SME guidance for a global financial services network. You will define standards, lead advanced troubleshooting, and steer network strategy and regulatory compliance across multi-vendor estates.

You will deliver architectural assurance, oversee lifecycle governance, and champion security postures while guiding L1-L3 engineers and collaborating with stakeholders to ensure operational

Qualifications

• 7+ years hands-on network engineering/architecture in regulated environments.
• Proven ability to define standards and lead complex troubleshooting.
• Advanced knowledge of SD-WAN, WAN, LAN/WLAN, VPN/SASE, load-balancing and security platforms.
• Strong understanding of compliance and regulatory frameworks.
• Excellent communication for governance and stakeholder engagement.

Responsibilities

• Lead complex troubleshooting and RCA across multi-vendor networks.
• Define and maintain config standards & security baselines.
• Oversee lifecycle management including firmware governance & audits.
• Mentor L1-L3 engineers with coaching and best practices.
• Provide design assurance for deployments across SDWAN, WAN, LAN/WLAN, VPN/SASE, and load-balancing.
• Guide automation initiatives including IaC pipelines and drift detection.
• Drive monitoring and telemetry enrichment to reduce MTTR.

Skills

Multi-vendor networking

Routing & HA design

Network security practices

IPAM/DNS/DHCP (Infoblox)

Automation/IaC (Python, Terraform, Ans

Stakeholder engagement

Architectural governance

Tools

Infoblox

SolarWinds

ServiceNow

CI/CD pipelines

Job description

Position Summary

The L4 Network Specialist provides technical leadership, architectural governance, and subject-matter expertise to ensure the stability, security, scalability, and evolution of the global network environment for financial services clients. This role is central to defining standards, leading advanced troubleshooting, and guiding network strategy and compliance in highly regulated environments.

Primary Purpose

Deliver architectural assurance, advanced support, and strategic direction for complex, multi-vendor network estates. Champion security posture, lifecycle governance, and the evolution of network services, ensuring regulatory and operational excellence.

Essential Roles & Responsibilities

• Lead complex troubleshooting and root cause analysis across multi-vendor network domains, acting as the highest escalation point
• Define and maintain configuration standards, security baselines, and golden templates to ensure compliance with financial services regulations
• Oversee lifecycle management including firmware governance, vulnerability remediation, and audit readiness
• Lead, mentor and develop L1-L3 engineers, fostering high performance through structured coaching, regular feedback, and the consistent application of best practices and continuous improvement initiatives.
• Provide design assurance for new deployments and service modernisation across SDWAN, WAN, LAN/WLAN, VPN/SASE, and load-balancing environments
• Support and guide automation initiatives including Infrastructure-as-Code (IaC) pipelines, compliance validation, and drift detection
• Drive monitoring and telemetry enrichment strategies to improve event correlation and reduce mean time to resolution (MTTR)

Financial Services & Regulatory Compliance

• Ensure all architectural and operational activities adhere to financial services regulations and frameworks (e.g., FCA, PRA, DORA, ISO 27001, SOC)
• Maintain robust documentation, audit trails, and compliance validation for all network changes and deployments
• Integrate regulatory requirements, security controls, and zero trust principles into network designs and operation
• Support risk assessments, compliance reviews, and operational audits as required

Governance & Reporting

• Lead stakeholder engagement and architectural governance, ensuring alignment with business priorities and regulatory requirements
• Produce and present architectural reviews, performance dashboards, and compliance summaries for internal and customer stakeholders
• Maintain and enrich CMDB through topology validation and asset reconciliation
• Guide monitoring and telemetry enrichment for improved visibility and governance

Key Skills

• Deep multi-vendor expertise (Cisco, Fortinet, F5, SASE platforms)
• Advanced routing, segmentation, and high-availability design (BGP, OSPF, ACLs, NAT, HA clusters)
• Network security best practices (least privilege, zero trust, vulnerability remediation)
• Experience with IPAM/DNS/DHCP platforms (e.g. Infoblox)
• Experience in implementing automation frameworks and CI/CD for network configuration (Python, Terraform, Ansible)
• Strong stakeholder engagement and governance skills
• Architectural review, capacity planning, and lifecycle management

Position Specifications - Technical

Essential:

• 7+ years' hands-on experience in network engineering, architecture, and support within financial services or regulated environments
• Proven experience defining standards, leading complex troubleshooting, and driving network evolution
• Advanced technical knowledge across SDWAN, WAN, LAN/WLAN, VPN/SASE, load-balancing, and security platforms
• Strong understanding of compliance, risk management, and regulatory frameworks
• Effective communicator, able to engage stakeholders and lead governance activities

Highly Desirable:

• Experience in managed service or telecom environments serving financial services clients
• Relevant certifications (CCIE, Fortinet NSE8, F5, SASE platform certifications)
• Experience with SolarWinds, ServiceNow, Infoblox, Zero-Touch Deployment, and CI/CD automation tools