Penetration Tester

Tesco; Welwyn Garden City; Hybrid; GBP 45,000 - 60,000; Full time

Job summary

A leading UK retail company in Welwyn Garden City is seeking a Cyber Security professional to enhance their internal penetration testing capabilities. This role involves performing security assessments on various systems and collaborating with application and infrastructure teams. Candidates should have penetration testing experience and strong analytical skills. Benefits include a generous bonus scheme, private medical insurance, and a focus on continuous development.

Benefits

Annual bonus scheme of up to 20%

Holiday starting at 25 days

Private medical insurance

Free 24/7 virtual GP service

Qualifications

• Experience performing authorised penetration tests.
• Understanding of operating system and networking fundamentals.
• Knowledge of preventative and detective controls.

Responsibilities

• Deliver high-quality security assessments.
• Work with security engineers on detections.
• Triage findings from bug bounty program.

Skills

Penetration testing experience

Analytical and critical thinking

Good communication skills

Education

Relevant industry certifications (GPEN, OSCP, etc.)

Tools

EDR

Firewalls

IDS/IPS

Job description

Overview

Tesco UK • Welwyn Garden City • Full-Time • Apply by 24-Nov-2025

We are passionate about step changing our cyber security capability to better protect customers and colleagues across our global business, and we're building an internal penetration testing function to complement and help further mature our defensive security capabilities.

This new role challenges you to use your offensive skills to discover and demonstrate vulnerabilities and weaknesses in our systems. Tesco Technology has hundreds of software and infrastructure engineers deploying solutions at scale using many different technology stacks, from traditional on-premise infrastructure to cloud-centric containerised deployments.

Working collaboratively with our developers is key to us identifying and addressing these findings, efficiently and at scale across Tesco.

You will have the opportunity to help application teams remediate issues, to help infrastructure teams to build better supporting functions and to help improve our detection and response teams by proposing new detection ideas or providing your offensive security knowledge to aid in incident response.

We believe that skilled and hard-working people are our greatest asset in reducing cyber risk to our business and customers.

We encourage and support continual development and recognise the importance of keeping up with the latest technology (as well as all the older stuff) and an evolving threat landscape.

What is in it for you

We're all about the little helps. That's why we make sure our Tesco colleague benefits package takes care of you - both in and out of work. Click Here to find out more!

• Annual bonus scheme of up to 20% of base salary
• Holiday starting at 25 days plus a personal day (plus Bank holidays)
• Private medical insurance
• 26 weeks maternity and adoption leave (after 1 year’s service) at full pay, followed by 13 weeks of Statutory Maternity Pay or Statutory Adoption Pay, we also offer 4 weeks fully paid paternity leave
• Free 24/7 virtual GP service, Employee Assistance Programme (EAP) for you and your family, free access to a range of experts to support your mental wellbeing

Responsibilities

You will be responsible for:
You'll be working in an offensively trained and defensively focused security team.
Your primary responsibility will be to deliver high-quality security assessments in a variety of areas including web application, API, mobile, and infrastructure.
But, unlike in a typical consultancy role, you'll also have the advantage of being able to use internal knowledge, data sources and tools to help identify attack vectors and be able to test out your hypotheses.

There will be other opportunities to stretch your skills:

• You could work with our security engineers to refine and develop our detections
• Participate in purple teaming exercises carrying out wider assessments of our security posture
• Help triage and validate findings from our bug bounty program
• Triage and validate Tesco's risk posture for newly released CVEs as part of vulnerability management

We support our colleagues on their career development and provide time and opportunities throughout the year to carry out research, as well as training supported by us to ensure you continue to develop and innovate in offensive security.

Qualifications

• Penetration testing experience performing authorised tests on computer systems, exposing weaknesses in security that potentially could be exploited.
• GPEN, CREST, OSCP, OSEP or other industry relevant certifications are helpful but not crucial.
• An understanding of operating system and networking fundamentals, and underlying principles
• Knowledge of preventative and detective controls (EDR, firewalls, IDS, IPS, anti-virus, etc)
• Analytical and critical thinking skills, willingness to challenge status quo
• Good written and oral communication skills
• To be comfortable working both independently, and collaboratively in a diverse team

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.

We are proud to have an inclusive culture at Tesco where everyone truly feels able to be themselves. At Tesco, we not only celebrate diversity, but recognise the value and opportunity it brings. We\'re committed to creating a workplace where differences are valued, and make sure that all colleagues are given the same opportunities. We\'re proud to have been accredited Disability Confident Leader and we\'re committed to providing a fully inclusive and accessible recruitment process. For further information on the accessibility support we can offer, please click here.

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. If you are applying internally, please speak to the Hiring Manager about how this can work for you - Everyone is welcome at Tesco.