Our Vision: Continue to be the leading UK mobile infrastructure services company. Our Mission: To be famous for excellence in delivery, embracing transformation with our people and our customers at its heart. We are at an exciting time in our company’s development. We've come a long way since we were first formed in 2012. From the rollout of new technologies and managing complex legislation affecting the industry, we are leading the conversation on innovation and developing sharper solutions to serve our customers better. We collaborate as a team to meet the high standards expected of us and demand the best of ourselves through our values. Drive the flow of supplier data into Cornerstone’s systems, ensuring accuracy, completeness, and timely reporting. You’ll turn raw data into clear, actionable insights that showcase supplier performance against key SLAs, milestones, and financial targets. Your reporting and analysis will directly inform strategic decisions across our Property & Estates, Acquisition, and Legal teams. What You’ll Do Capture and maintain accurate supplier data in Siterra and the Data Warehouse, ensuring integrity through robust validation and programme‑level standards. Develop clear, insight‑driven reports and dashboards using Excel and Power BI to track SLAs, milestones, and financial targets. Analyse data trends to create compelling, actionable insights for senior stakeholders. Champion best‑practice data management in Siterra, driving automation and continuous process improvement. Partner with Property & Estates, Acquisition, and Legal teams to meet operational and compliance reporting needs, acting as a key liaison for supplier data queries. Ensure all data processes align with governance and regulatory requirements, supporting audits with accurate performance evidence. What You’ll Bring Highly experienced in data management, reporting, or analytics within volume based programmes and projects. Experience in data management and reporting within roperty, estates, or legal environments. Experience in telecoms sector. Supplier data management experience. Advanced Excel, Power BI, and familiarity with project management tools. Why Join Us?. Step into a role where your expertise makes an immediate impact. At Cornerstone, you’ll join a fast‑moving, highly collaborative environment where your insights help shape the future of the UK’s digital infrastructure. You’ll work with passionate teams, tackle meaningful challenges, and take ownership of work that truly drives results. If you’re looking for a contract role that’s dynamic, empowering, and gives you the platform to do your best work—this is it. Our commitment to Equity, Diversity, and Inclusion (EDI) is fundamental to our success. We strive to cultivate an inclusive environment where every employee feels valued, respected, and empowered. By embracing unique perspectives and experiences, we drive innovation and drive our organisation forward, therefore, we recognise the importance of welcoming applications from candidates of all backgrounds. We want to ensure everyone is able to present their best self throughout the recruitment process so if you require any adjustments, please let us know. If this role is of interest to you and you would like to find out more, please do apply with an up to date version of your CV.