Senior Infrastructure Engineer

Date: 24 Sept 2026

Location: Pier Walk, North Greenwich, TfL Corporate

Company: TfL, GLA or OPDC

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Key Information

 

Job title: Senior IT Network Assurance Engineer  

Salary: £70,000 - £75,000 plus fantastic benefits                            Grade: Band 3 

Contract type: Permanent                                                               Reference: 5654  

Team: Service Owner - Networks and Hosting                                  Directorate: TfL Corporate

Contract details: TfL                                                                        Location:  Pier Walk, North Greenwich / Hybrid

Application closing date: Thursday 1st October 2026  

 

All offers of employment are subject to satisfactory right‑to‑work checks.  Candidates must be able to demonstrate their right to work in the UK.  At the present time TfL is unable to offer visa sponsorship for this role.  

 

Hybrid working within this role enables a balance of 50 per cent of time split between the office and home over a 4-week period. Hybrid working arrangements can evolve subject to business requirements. 

 

Key Technologies: Routing and Switching (WAN/LAN/Datacentre), SDN (Software Defined Networking), Network Security (Firewalls), Wi-Fi, Network Monitoring/Management Tools, and Cloud Networking. 

 

About Us 

The Networks and Hosting Team, which sits within Technology Products and Operations is responsible for maintaining existing infrastructure, which underpins the majority of our services across TfL.  

 

It is an exciting time to join the Network team, as you’ll be working on large scale network improvement projects such as: network security (firewall) upgrades, network consolidation and upgrades, WAN refreshes, data centre network refresh. 

 

About the Role 

The Senior IT Network Assurance Engineer reports to the Network Assurance Manager and provides specialist technical knowledge, experience and leadership to assure, support and optimise our IT Access, WAN, data centre and Cloud network infrastructure. 

 

Working within a 24/7 operational environment the Senior IT Assurance Engineer will be maintaining technologies, assuring deployments, and looking for continuous improvement and automation of repeatable tasks.

 

You will have an in depth very high level knowledge of networking technologies including routing and switching across campus and datacentre, and network security (inc. firewalls), and will be leading Network Assurance team members, and collaborating with our Network Transformation Portfolio, Infrastructure teams, Product Managers, Network Architects, Cyber Security specialists, and our Application Support and Development teams to provide expertise to support our business-critical services and deliver high profile projects in line with our organisation priorities and vision. 
  

Main Duties 

 

  • Ensure the operability of TfL's information technology networks including management, investigation and resolution of incidents, and root cause analysis, to maximise system availability for critical business services in accordance with the agreed service levels.
  • Accountable for the technical ownership and assurance of all operational network activities, including change, request and network design architectures, ensuring networks are in line with approved designs, and implementations are fit for purpose.
  • Provide guidance and technically lead and mentor the Network team in the delivery of: BAU Services, Project work activities, Continual improvements to both processes and service.
  • Responsible for effective time management to develop skills, and provide technical leadership and role model behaviour to junior members of the team wishing to progress.
  • Deliver proactive lifecycle and capacity management:  Identify and drive activities to mitigate risks in the Network environment.
  • Lead on the accurate and timely reporting of the state of the technical environment using monitoring and reporting tools, rectifying any operations that are running outside of their normal state. Ensure all HW, SW and service configuration elements are recorded correctly.
  • Service and Process Improvements; Identify, shape and drive the delivery of potential areas of improvement to technology or processes, with particular focus on, standardising and automation to reduce manual effort. Provide recommendations for innovative solutions.
  • Collaborate & engage with other technology colleagues and teams to deliver project outcomes. Provide SME input and contribute to the design process, as required.
  • Identify technical dependencies, risks, and issues to maintain vendor, statutory and TP&O compliance levels.
  • Responsible for identifying trends and forecasting activity, proactively carrying out improvements to assist TfL in maintaining up to date, stable and secure technologies.
  • Supplier Management: Handle suppliers’ adherence to Service Level Agreements, and work with vendors to minimise service disruption and achieve the minimum service according to the business requirements, and ensure value is realised.
  • Assure network activities meet TfL policies and standards, and best practices.
  • Ensure networks spend is in line with business priorities and is cost efficient.
  • Maintain knowledge of industry developments and trends in Network technologies. 

 

Knowledge and Skills 

 

Essential

  • The successful candidate will have a demonstrable very high level of knowledge of networking technologies including: 
        switching technologies (VLANs, trunks, STP, vPC, VDC, VXLAN, multi-layer switching and EtherChannel) 
        routing technologies (EIGRP/OSPF/iBGP/eBGP) and router redundancy (HSRP, VRRP, GLBP) 
        QoS in a LAN/WAN environment.
  • Demonstrable strong knowledge supporting firewalls including policy, and virtual private networks (VPN), and the use of the CLI to manage devices.
  • Understanding of SDN (Software Defined Networking), and cloud networking technologies/concepts.
  • Understanding of networking monitoring and management protocols inc. SNMP, and working knowledge of networking monitoring and management platforms such as Solarwinds.
  • Strong troubleshooting and problem solving skills, the ability and desire to learn new things and a willingness to work both autonomously and using their own initiative.
  • Knowledge of supporting Cisco and major firewall vendors’ software and hardware.
  • Highly skilled at analysing data to determine trends and patterns to proactively mitigate service affecting issues, as well as solving complex challenges.
  • Able to communicate coherently throughout, adapting the communication style to meet the varying audience, such as relating technical terms to non-technical people.
  • Proficient in risk identification and mitigation planning to reduce service impacting issues.
  • Proven ability to work with suppliers, internal teams and customers as necessary to reliably deliver component technologies that combine to form business services.
  • Mentoring & coaching skills to support Engineers with development of their technical skills. 

 

Desirable 

  • Advanced knowledge of SDN, cloud networking technologies, Wi-Fi and network automation techniques such as python.
  • Knowledge of supporting software and hardware from other major networking vendors.
  • The relevant national and international legislation pertaining to the Government/Public Sector IT – e.g. Data Protection Act, EU Procurement Directives and Freedom of Information Act is desirable. 

 

Experience 

 

Essential 

  • Experience of supporting large scale, high performance, high availability network architectures
  • Experience working with and understanding complex network architecture designs, and implementing updated versions of technology in line with approved designs.
  • Experience of Cisco network technologies and network security in complex enterprise sized environments.
  • Experience of working as a senior member of a technical team reporting to Management level, with an ability to technically lead and mentor a team of Engineers, acting as a technical authority and supporting technical development & progression within the team.
  • Experience working with Senior stakeholders to enable business benefit through IT service delivery.
  • Highly experienced in planning own activities, and demonstrable personal development planning.
  • Fluent in English and be fully conversant with technical language relating to network design and hardware 
  • Degree in a relevant subject, or equivalent qualifications/5 years+ work experience are essential 
  • Knowledge of ITIL and its practical implementation in large organisations. 

 

Desirable

  • In depth knowledge of the latest and emerging technologies and methodologies likely to be employed in designing and delivering enterprise wide networking solutions is highly desirable.
  • Commercial and Financial awareness, to enable strategic thinking in problem solving and the right solutions.
  • Experience as a lead IT Senior Engineer or Technical Architect is highly desirable.
  • Knowledge of agile methodologies, such as Scrum. 

 

 

Application Process 

  • Please apply using your CV  

  • Think carefully about the skills, knowledge and experience in the advert and cover this in your CV 

 

Equality, diversity and inclusion 

We are committed to equality, diversity and inclusion and aim to reflect the diverse communities we serve. We believe that a diverse workforce enables us to deliver better services and outcomes. Our goal is to make our recruitment as inclusive as possible. As a Disability Confident Leader, we actively encourage applications from disabled people. As part of the Disability Confident scheme, we aim to offer an assessment or interview to candidates who apply via the scheme where the minimum essential criteria for skills, knowledge and experience has been met. In some circumstances, it may not be practical to offer an interview or assessment to every candidate who applies through the scheme and meet the minimum essential criteria; in these situations, we select candidates who best meet the minimum criteria for the job rather than interviewing all who meet them. 

 

Across all recruitment activity, we recognise that selection methods may vary depending on the nature and scale of the campaign and will be applied fairly, consistently and proportionately in line with our Disability Confident commitments.   

 

We also use anonymising software that removes identifying information from CVs and cover letters to make the process fair. 

 
Benefits 
In return for your commitment and expertise, you will enjoy excellent benefits and scope to grow.  Rewards vary according to the level of role but mostly include the below:
 
Final salary pension scheme 
Free travel for you on the TfL network 
Reimbursement of 75% of the cost of a standard class Ticket for National Rail travel from home or 75% reimbursement on a 28-day flexi ticket
30 days annual leave plus public and bank holidays 
TfL is committed to work-life balance, operating a hybrid working approach where business and role requirements allow
Private healthcare discounted scheme (optional) 
Tax-efficient cycle-to-work programme
Retail, health, leisure and travel offers 
Discounted Eurostar travel
 
Hybrid working within this role enables a balance of 50 per cent of time split between the office and home over a 4 week period. Hybrid working arrangements can evolve subject to business requirements. 

We will make every effort to give you as much notice as possible, however some interviews/assessments could be organised at short notice.

 

Vetting Process 

At Transport for London, safety, trust and fairness sit at the heart of how we recruit. Our Vetting Charter (https://tfl.gov.uk/corporate/careers/our-vetting-process) explains the checks we carry out before you join us, helping ensure we create a safe, inclusive and reliable network for everyone who depends on our services. We simply ask that the information you provide is honest and accurate so we can progress your application smoothly. If something doesn’t match or can’t be verified, we may not be able to move forward with your application, but we’ll always treat you with transparency, respect, and clear communication throughout.