Senior Application Security & Pen Testing Lead

Allwynuk; Watford; On-site; GBP 70,000 - 110,000; Full time

Benefits offered by this job

26 days annual leave

Private medical insurance

Wellness allowance £500

Pension matched up to 8.5%

Dedicated learning & development

Job summary

Allwyn UK is seeking a senior security testing specialist to strengthen our application security and offensive security capability. You will focus on testing modern applications, APIs, and backend services, with additional work on purple team activities and adversary-led assessments.

You will lead, mentor and shape testing standards while collaborating with development teams to translate risks into actionable fixes.

Qualifications

• Strong hands-on experience in application penetration testing across web apps, APIs and service-based architectures.
• Strong understanding of Java-based backend systems, especially Spring Boot and microservices.
• Experience testing API gateways and Backend for Frontend layers, including authentication and data validation.
• Practical knowledge of cloud hosted apps, ideally AWS, with containerised services.
• Good understanding of modern web/mobile patterns and data exposure risk.
• Strong Linux and Windows knowledge including privilege escalation paths and exploitation approaches.

Responsibilities

• Lead and deliver advanced penetration testing across web apps, RESTful APIs and backend services.
• Assess Java-based backends, Spring Boot, microservices architectures and API gateways.
• Test authentication, authorization, orchestration and data validation across digital journeys.
• Test cloud hosted and containerised environments, ideally AWS.
• Review outputs from SAST/DAST and communicate risk prioritisation to developers.
• Support threat modelling and design reviews with testing scope mapping.
• Provide remediation guidance and risk-based sign-off inputs for releases.
• Help develop practical application security testing standards and playbooks.

Skills

Application penetration testing

Offensive security

Cloud security AWS

Linux/Windows hardening

Tools

SAST/DAST tools

Job description

Allwyn UK is seeking a senior security testing specialist to strengthen our application security and offensive security capability. You will focus on testing modern applications, APIs, and backend services, with additional work on purple team activities and adversary-led assessments.

You will lead, mentor and shape testing standards while collaborating with development teams to translate risks into actionable fixes.