Certes Computing Ltd

Senior Network Engineer (DV Cleared) Location: Milton Keynes Duration: 6-Months Rate: £540 per day (Inside IR35) Clearance: Active DV Clearance Required Working Pattern: Onsite 5 days per week Overview We are seeking an experienced Senior Network Engineer to support a range of highly secure Government platforms and services within a complex enterprise environment. The successful candidate will join a wider team of skilled technical specialists, providing both BAU support and project delivery across critical infrastructure and network technologies. This role requires strong experience working within secure and air-gapped environments, with responsibility for the design, implementation, administration, and support of enterprise network and infrastructure solutions. The position will also act as an escalation point for complex technical issues and contribute to ongoing modernization and security improvement initiatives. As the Senior Network Engineer you will be responsible for designing, implementing, securing, and maintaining enterprise network infrastructure with a focus on high availability, performance, and resilience. This role provides advanced technical leadership across routing, switching, Firewall administration, and network security operations. You will serve as an escalation point for complex issues involving Cisco switching platforms, Cisco Firepower Threat Defense (FTD), and Palo Alto Networks Next-Generation Firewalls, Catepan encryption devices Key Responsibilities * Design, implement, support, and maintain secure enterprise network infrastructure * Deliver BAU operational support alongside project-based infrastructure changes * Manage and optimise enterprise LAN/WAN environments * Administer and support Cisco switching and routing technologies * Configure and maintain network security technologies including Cisco Firepower/ASA and Palo Alto Firewalls * Support network security operations including IPS/IDS, VPNs, IPsec, SSL, and PKI technologies * Troubleshoot complex network, connectivity, and security-related incidents * Support network modernization, migration, and automation initiatives * Ensure compliance with security standards, policies, and hardening guidelines * Work collaboratively with cross-functional technical and security teams * Support virtualised infrastructure and software-defined networking technologies * Maintain network monitoring, alerting, and configuration management platforms Required Skills & Experience * Proven experience supporting and designing infrastructure within highly secure or air-gapped environments * Strong experience with Cisco switching and routing technologies * Hands-on expertise with Cisco Firepower/ASA Firewall installation and administration * Experience administering Palo Alto Firewalls and Panorama * Strong understanding of network security technologies including IPsec, SSL VPNs, PKI, and IDS/IPS * Experience with VMware virtual environments and virtual networking solutions * Knowledge of NSX-T platforms * Experience using network monitoring and configuration tools such as SolarWinds NCM, PRTG, and KIWI * Experience supporting encryption devices including Catapan and Bulldog technologies * Familiarity with Cisco collaboration technologies including CUCM, CSM, CMM, Expressways, VTC, and DeskPro devices * Experience with copper and fibre optic patching * Strong understanding of Windows infrastructure services including: - Active Directory - DNS - DHCP - NPAS - Certificate Services * Experience with Software Defined Access technologies including Dot1X and IBNS 2.0 Desirable Experience * Knowledge of NIST hardening guidelines * Understanding of ITIL processes and best practices * Experience with ServiceNow * Familiarity with BeCrypt OS * Linux administration knowledge * Experience with data diode technologies Candidate Profile The ideal candidate will be a proactive and technically strong infrastructure professional with experience operating in secure Government or defence environments. You will be comfortable working onsite full-time, handling complex technical challenges, and contributing to both operational support and strategic infrastructure initiatives. If this role is of interest please email your CV to: (see below) Certes Computing (and all of its subsidiary companies) is committed to promoting equality and diversity in its business operations.

SharePoint and Entra ID Administrator (SC Cleared) Duration: 4 Weeks Rate: £500 -£600 per day (negotiable) Location: Remote working IR35 Status: Outside Start: ASAP Project Overview: We require a SharePoint and Entra ID Administrator (SC Cleared) for our public sector client to change their organisation level SharePoint sharing settings. A Helix Moss SharePoint Server has been taken offline and replaced with a manual service provision. Hence the first phase will enable the SharePoint external sharing model with Microsoft Entra Business-to-Business (B2B) integration. Only one SharePoint site will be shared in the live environment. Access to all remaining SharePoint Online sites will be restricted to internal sharing by configuring and restricting the external sharing settings at the site level. The role will involve you working alongside the Clients M365 Engineer, and demonstrate requirements are initially met in a test environment before approval and release to the live environment following change release procedures. Provide assurance, impact analysis, risk assessment, advice, assistance with communications, document outcomes and deliverables, share knowledge and provide a thorough documented handover. Ensuring the inhouse capability can replicate the activity on exit. The Client needs to ensure that files are shared to the right people, prevent over sharing and being able to share confidential or other sensitive data safely with only those who should have access to it. The Client needs the appropriate safeguards implemented to protect their sensitive information and to ensure that all people outside of their organisation are managed and must authenticate. Experience and Deliverables include: As the SharePoint and Entra ID Administrator (SC Cleared) you will: Enable a SharePoint external sharing model with Microsoft Entra B2B integration. Only one SharePoint site will be shared in the live environment. Access to all remaining SharePoint online sites will be restricted to internal sharing by configuring and restricting the external sharing settings at the site level. Scope of work For the scope of work below you will work alongside the Clients M365 Engineer to complete this Phase. To understand the Clients requirements To oversee the production of the low-level configuration and guidance documentation and gain approval To oversee the implementation of the recommended configuration in their test M365 tenancy To ensure appropriate testing is undertaken To ensure knowledge transfer of all aspects throughout engagement To assist in preparation and impacting for live M365 tenancy implementation To oversee live implementation when ready to do so Key Outcomes/Deliverables Changes rolled out to test and live environment following the Clients Change and release processes. Documentation reflecting the final configuration. Documented knowledge transfer to the M365 Engineer team is a key outcome to ensure long-term technical support. *Due to the nature of the role and timescales required candidates need to possess current SC Level Security Clearance for this role* To apply to this role please call Joanne Stanley or email: (see below) Certes IT Service Solutions welcome applications from all sections of the community and from people with diverse experience and backgrounds Certes Computing (and all of its subsidiary companies) is committed to promoting equality and diversity in its business operations.