Senior Infrastructure & Network Engineer

Job Description

Role overview 

You will own the most complex infrastructure and network issues across on-premises, AWS, Azure and hybrid environments, acting as the final technical escalation point before vendors. 

Alongside operational ownership, you will play a lead engineering role in a multi-year cyber security uplift programme: rolling out Zscaler SASE (ZIA, ZPA), retiring Always-On VPN, and bringing customer remote access services in line with Zero Trust controls.

Key responsibilities 

Senior escalation and technical leadership 

• Act as the Level 3 escalation point for Level 1 and Level 2 teams, owning critical incidents, major problems and complex service requests through to resolution. 

• Lead technical bridges during major incidents, coordinating engineers, vendors and stakeholders and communicating impact clearly to management. 

• Mentor Level 2 engineers, review their fixes and build team capability through documented troubleshooting approaches. 

• Set technical standards for network, server and cloud configuration, and review changes raised by other engineers. 

Qualifications

SASE / SSE and Zero Trust (programme duties) 

• Engineer and operate the Zscaler platform: ZIA for internet and SaaS security, ZPA for private application access. 

• Deploy and maintain ZPA App Connectors in AWS, including integration with AWS Transit Gateway to reach customer jump service environments. 

• Lead phased migration of users from Always-On VPN to ZPA, including pilot groups, parallel running, rollback planning and final decommissioning of RRAS infrastructure. 

• Integrate Zscaler with Microsoft Entra ID for authentication, user group policy and conditional access. 

• Configure ZIA policy for URL filtering, SSL inspection, DLP enforcement and AI application controls, working with Security Operations on tuning and exceptions. 

• Deploy and support Zscaler Zero Trust Branch and SD-WAN appliances at office sites. 

• Work directly with Zscaler Professional Services and implementation partners during deployment, then take ownership of the platform as business-as-usual. 

• Produce design documents, runbooks and knowledge transfer material so Level 1 and Level 2 teams can support the platform after go-live. 

• Administer and troubleshoot AWS and Microsoft Azure: VPCs and VNets, Transit Gateway, routing, security groups, compute, identity and service availability. 

• Support Windows Server and Linux estates, including Active Directory, patching, hardening and performance diagnosis. 

• Support virtualisation, storage and backup platforms, and lead upgrades and patching through change control. 

• Cloud and server infrastructure 

  Problem management and improvement 

• Lead root-cause analysis for major and repeat incidents, and track remediation actions to closure. 

• Improve monitoring and alerting coverage across network, SASE and cloud layers. 

• Automate repetitive tasks with PowerShell, Python or Bash, and use infrastructure-as-code where it reduces configuration drift. 

• Apply security, compliance and change management processes across all environments. 

• Support vulnerability remediation, Cloud Security Posture Management findings, audits and ISO 27001 evidence gathering. 

• Escalate risks and service-impacting issues promptly to the Programme Director, Security Lead and management. 

• Security, risk and compliance 
  
  Role and Responsibility 

• We are looking for 8+ years in infrastructure, networking or cloud roles within complex IT environments, including at least 3 years at senior or Level 3 escalation level. 

• Hands-on SASE or SSE deployment and operational experience; Zscaler (ZIA, ZPA) strongly preferred, with Netskope, Palo Alto Prisma Access or Cloudflare One also considered. 

• Hands-on configuration and troubleshooting experience with at least two of: Juniper (Junos), Fortinet FortiGate, Palo Alto Networks (PAN-OS). 

• Strong networking knowledge: TCP/IP, DNS, DHCP, BGP, OSPF, switching, firewalls, IPsec and SSL VPN. 

• Hands-on administration of both AWS and Microsoft Azure, including cloud networking (Transit Gateway, VNet peering, hybrid connectivity). 

• At least one cloud certification at associate level or higher (e.g. AWS Solutions Architect Associate, Azure Administrator Associate, Azure Network Engineer Associate). 

• Proven experience supporting Windows Server and Linux environments. 

• Experience integrating network access with identity platforms, ideally Microsoft Entra ID. 

• Track record of leading infrastructure migrations or VPN replacement projects from pilot to full rollout. 

• Ability to interpret logs and packet captures and isolate faults across on-premises, cloud and SASE paths. 

• Clear communication with technical and non-technical stakeholders, including vendors and customers. 

  Desirable 

• Zscaler certifications: Zscaler Digital Transformation Administrator (ZDTA) or Engineer (ZDTE). 

• Vendor certifications: Palo Alto PCNSE, Fortinet FCP or FCSS (formerly NSE 4 to 7), Juniper JNCIS or JNCIP. 

• Experience with SD-WAN and Zero Trust branch deployments. 

• Experience with DLP, SSL inspection policy design and Microsoft Purview integration. 

• Infrastructure-as-code experience (Terraform, Ansible) and scripting in PowerShell, Python or Bash. 

• Interest in applying AI tools responsibly to infrastructure operations and diagnosis. 

• Experience supporting customer-facing remote access or managed service environments. 

• Calm and methodical under pressure, with confidence to own unfamiliar problems and drive them to resolution. 

Additional Information

Why Version 1? 

 At Version 1, we believe in providing our employees with a comprehensive benefits package that prioritises their wellbeing, professional growth, and financial stability. 

• Share in our success with our Quarterly Performance-Related Profit Share Scheme, where employees collectively benefit from a share of our company's profits 
• Strong Career Progression & mentorship coaching through our Strength in Balance & Leadership schemes with a dedicated quarterly Pathways Career Development programme 
• Flexible/remote working, Version 1 is tremendously understanding of life events and people’s individual circumstances and offer flexibility to help achieve a healthy work life balance 
• Financial Wellbeing initiatives including; Pension, Private Healthcare Cover, Life Assurance, Financial advice and an Employee Discount scheme 
• Employee Wellbeing schemes including Gym Discounts, Bike to Work, Fitness classes, Mindfulness Workshops, Employee Assistance Programme and much more. Generous holiday allowance, enhanced maternity/paternity leave, marriage/civil partnership leave and special leave policies 
• Educational assistance, incentivised certifications, and accreditations, including AWS, Microsoft, Oracle, and Red Hat 
• Reward schemes including Version 1’s Annual Excellence Awards & ‘Call-Out’ platform. 
• Environment, Social and Community First initiatives allow you to get involved in local fundraising and development opportunities as part of fostering our diversity, inclusion and belonging schemes. 

And many more exciting benefits… drop us a note to find out more.    

Version 1 is an equal opportunities employer. 

We are committed to building a diverse, inclusive and respectful workplace where everyone feels valued and able to thrive. We welcome applications from people of all backgrounds, identities and lived experiences, and we value the different perspectives people bring including those shaped by disability and neurodiversity. 

We want every candidate to have a positive and accessible recruitment experience. If you need reasonable adjustments at any stage of the process, please contact your recruiter at Version 1. We will consider all requests carefully, respectfully and confidentially. 

Video links: 

https://www.youtube.com/watch?v=F_d3ELTH5zo