AI Security Tester

Mastek; Reading; Hybrid; GBP 70,000 - 100,000; Full time

Job summary

Mastek is seeking an AI Security Tester who can break AI systems before adversaries, simulating attacks to reveal vulnerabilities in AI/ML solutions.

You will work in a hybrid role, travel as needed to offices or customer sites, and apply offensive security, threat modelling, and robust data privacy controls to safeguard deployments.

Qualifications

• 5+ years in offensive cybersecurity (AppSec, Pen Testing, Red Teaming)
• Minimum 2 years focused on AI/ML security
• Strong programming in Python and Java
• Experience with ML frameworks and AI tooling

Responsibilities

• Conduct adversarial testing to challenge AI model safety and guardrails
• Perform penetration testing and fuzzing of AI systems
• Identify data poisoning, model evasion, hallucinations, and bias
• Validate data privacy controls including PII handling and encryption
• Document vulnerabilities and evidence in lower environments

Skills

Offensive cybersecurity

AI/ML security

Python

Java

Penetration testing

Red Teaming

Adversarial testing

Fuzzing

Threat modelling

Data privacy

Education

Master’s degree in Computer Science, Cybersecurity, AI/ML, or related field

Tools

PyTorch

TensorFlow

LangChain

LlamaIndex

Red-teaming toolkits

Job description

Are you passionate about breaking AI systems before adversaries do? We’re looking for an AI Security Tester with deep offensive security expertise to help safeguard next-generation AI solutions.

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 Mastek offices or customer location

• 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
• 5+ years in offensive cybersecurity (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