Penetration Tester

We are currently hiring a AI Security Tester for an exciting client engagement.

Role: AI Security Tester

Location: Reading , UK (Hybrid Role, when needed will have to travel to Mastek offices or customer location)

Positions: Permanent

Clearance: SC Cleared / Eligible

Role Overview

In this role, you’ll simulate real-world attacks to uncover vulnerabilities in AI/ML systems. From stress-testing model guardrails to identifying data privacy risks, you’ll play a critical role in ensuring secure and trustworthy AI deployments.

Working Model

Hybrid Role, when needed will have to travel to Client offices or customer location

What You’ll Do

Conduct adversarial testing to challenge AI model safety and guardrails Perform penetration testing and fuzzing of AI systems Identify risks such as data poisoning, model evasion, hallucinations, and bias Validate data privacy controls, including PII handling and encryption Simulate attack scenarios and exploit attempts Document vulnerabilities, unexpected behaviours, and evidence in lower environments Analyse threat vectors and recommend mitigation strategies

Key Requirements

• 5+ years in offensive cyber security (AppSec, Pen Testing, Red Teaming)
• Minimum 2 years focused on AI/ML security
• Strong programming skills in Python / Java
• Hands-on experience with ML frameworks (e.g., PyTorch, TensorFlow)
• Familiarity with AI tooling (e.g., LangChain, LlamaIndex, red-teaming toolkits)
• Proven ability to assess and secure AI systems end-to-end

Nice to Have

• Master’s degree in Computer Science, Cybersecurity, AI/ML, or related field
• Certifications such as CISSP or AI security/safety credentials