Security Engineer II - Detection Engineering

Tesco UK • Welwyn Garden City • Hybrid • Full-Time • Apply by 03-Oct-2025 About the role As a Cyber Security Detection Engineer, you will lead the development, implementation, and continuous improvement of Tesco's cyber security detection capability. You will be required to understand the changing threat landscape, see opportunities for improvement in existing detections, establish new detections, and ensure appropriate detection coverage for the organisation. You will work closely with multiple teams, including security operations, engineering, and risk & compliance, in a fast paced and agile environment. What is in it for you We offer excellent benefits that help make Tesco a great place to work. These include but aren't limited to: An annual bonus scheme which you can achieve up to 20% of base salary Colleague Clubcard (including a 2nd card for a family member) after 6 months service with 10% off most purchases at Tesco Holiday starting at 25 days plus a personal day A retirement savings plan - 4%-7.5% contribution rate Life Assurance - 5 x contractual pay Buy As You Earn Scheme Save As You Earn Scheme Deals & Discounts through Tesco including Tesco Mobile & Tesco Bank Deals and Discounts through many other external businesses You will be responsible for Responsible for developing and driving the cyber security detection capability both day-to-day and strategically for the Tesco Group. You are expected to seek out effective and comprehensive detection logic and capability, ensuring detections are robust and not brittle, thoroughly tested, and that alerts and supporting information is available to and understood by operational cyber security teams. You are expected to put the needs of operational teams and incident responders at the centre of your development work, ensuring detections and alerts are relevant, of value, and have practical response steps. You will need to ensure detection capability is fit for both on-premises, private and public cloud environments, working at significant scale, and across a diverse range of asset types. In addition, you may provide support during cyber security incidents, participate in threat hunts, and work with other security teams to deliver automation and standardisation to improve efficiency and response. You will need Security Engineering Skills •Threat Led oAbility to assess and validate information from various sources on cyber and informational security threats to business. oAbility to analyse and identify significance of processed intelligence to identify trends, threat actor TTPs and potential capabilities. oAbility to break down and translate information into tangible actionable data. •Secure & Test-Driven Engineering oUnderstanding of cyber security threat frameworks such as MITRE ATT&CK, Lockheed Martin Killchain etc. oAbility to specify/implement processes to maintain required level of security for a component/product/system during its lifecycle. oProficient at detection development lifecycle covering all reasonable positive and negative test cases. oAbility to conducts code reviews of existing content and processes to identify and enhance or mitigate security issues. oContribute to security evaluation of or testing of threat/vulnerabilities faced by systems. oApplies recognised evaluation/testing methodologies, tools and techniques to signature development / reviews, suggesting new ones where appropriate. •Research oAbility to quantify and define research goals to generate worthwhile relevant detection ideas for further testing and exploration. oAbility to summarise findings or technical information to be disseminated with wider teams, factoring in business knowledge and summaries. Experience relevant for this job: Key Skills and Experience •An ability to develop queries and enable robust detection of threats. •Working knowledge of Windows, macOS or Linux operating systems •Ability to work independently as well as part of a team. •Understanding of modern attacker TTPs •Translate threat intelligence into actionable detection logic. •Solid grasp of detection technologies •A broad understanding of security concepts; an interest and passion for cyber security •An analytical approach; ability in problem solving and comfortable working on production systems at scale. •Query languages such as KQL or SPL •Experience developing and maintaining basic automation scripts (., Bash, Python, Batch, PowerShell Desirable Skills and Experience: •Knowledge of cloud infrastructure, cloud security and cloud APIs a plus •Knowledge of attacker tools and evasion techniques within offensive engineering •Working knowledge of at least one major programming language, including scripting languages like Python and PowerShell •Experience of developing detections as code Desirable Certifications •One or more from: CompTIA Security+, GIAC, CEH, SSCP. Where appropriate other industry relevant certifications will be considered. About us Our vision at Tesco is to become every customer's favourite way to shop, whether they are at home or out on the move. Our core purpose is'Serving our customers, communities and planet a little better every day'. Serving means more than a transactional relationship with our customers. It means acting as a responsible and sustainable business for all stakeholders, for the communities we are part of and for the planet. Diversity, equity and inclusion (DE&I) at Tesco means that whoever you are and whatever your background, we always want you to feel represented and that you can be yourself at work. In short, we're a place where Everyone's Welcome. We're proud to have been accredited Disability Confident Leader and we're committed to providing a fully inclusive and accessible recruitment process. We're a big business and we can offer a range of diverse full-time & part-time working patterns across our many business areas, which means that we can find something that works for you. We work in a more blended pattern -combining office and remote working. Our offices will continue to be where we connect, collaborate and innovate.