Operational Acceptance Testing Tester

We are seeking an experienced OAT Tester to join our team supporting the Network modernisation Programme.

You will perform Operational Acceptance Testing across newly deployed Juniper wired and wireless networks, validating that implementations meet design specifications, performance requirements, and operational readiness standards before handover to business-as-usual support.

You will act as the critical link between physical deployment teams and user acceptance testing teams, focusing on non-functional validation alongside a foundational understanding of Layer 2/Layer 3 networking and Wi-Fi access points., * OAT Delivery: Execute structured non-functional testing for wired and wireless networks post-cutover, after NRFU (Network Ready For Use) confirmation is received - covering performance, stability, capacity, security, roaming, and resilience.

• Dual-Tier Validation: Verify two distinct test levels consistently across all sites:
• Building/Site Level: Confirm approved network designs are applied correctly; audit switch/AP configurations; validate site-specific settings, monitoring alerts, and deployment accuracy.
• Solution Level: Verify end-to-end solution behaviour including failover, throughput, latency, VLAN segmentation, backup paths, and compliance with agreed standards.
• Testing Scope: Focus on non-functional attributes (performance, stability, interoperability, maintainability) - functional end-user device testing is handled by separate UAT teams.
• Evidence & Reporting: Capture test evidence (screenshots, throughput data, heatmaps, ping/traceroute logs), complete standardised test checklists, raise defects via JIRA, and sign off acceptance criteria where met.
• Stakeholder Collaboration: Work alongside network engineers, cutover teams, SIAM, and UAT testers to resolve queries, clarify scope, and ensure alignment with agreed acceptance rules.
• Process Adherence: Follow the approved OAT Test Strategy, maintain auditable records, and support lessons learned reviews to improve testing across subsequent building migrations.

• Essential: Practical experience of non-functional testing principles and practices within IT/network environments.
• Essential: Working knowledge of Layer 2/Layer 3 networking fundamentals (VLANs, IP addressing, routing, switching) and Wi-Fi access point deployment and configuration (802.11 standards, SSIDs, roaming, RF basics).
• Essential: Ability to use common network test tools (ping, iperf, throughput testers, wireless survey tools) and interpret basic monitoring output.
• Essential: Strong attention to detail; ability to follow defined processes and document results clearly for technical and non-technical stakeholders.
• Desirable: Awareness of Juniper networking equipment (switches, WLCs, APs) or experience in higher education/public sector IT projects.
• Desirable: Understanding of IT service management tools (ServiceNow, JIRA, SolarWinds) and concepts like SIAM, warranty, and hypercare support.

• Our competitive salary packages feature pension, health care, life assurance, laptop, phone, access to extensive training resources and discounts within the larger Tata network.

At TCS, we believe in building and sustaining a culture of equity and belonging where everyone can thrive. Our diversity motto is ‘Inclusion without Exception’.

You’ll find a welcoming culture and many internal volunteering and social networks to join. Our diversity, inclusion and social activities include LGBTQ+ and mental health networks, as well as health and wellness initiatives and sports events (we even sponsor the London Marathon).

TCS celebrates inclusion without exception.

TCS is a purpose-led transformation company, built on belief. We don’t just help businesses to transform through technology. We support them in making a meaningful difference to the people and communities they serve - our clients include some of the biggest brands in the UK and worldwide. For you, it means more opportunities to make an impact that matters, through challenging projects which demand ambitious innovation.