Security engineer, application security (UK)

The role

You will build security foundations for AI systems and protect AI infrastructure. You will conduct threat modeling, manage application security programs, and partner with engineering teams to embed security into code.

What you will do

• Conduct threat modeling sessions with product teams
• Design secure architectures for new features
• Establish and maintain SAST/DAST scanning in CI/CD pipelines
• Conduct security code reviews for critical changes
• Build automation to catch vulnerabilities before production
• Partner with engineering teams to establish secure coding standards
• Design and recommend security features and products for customer environments
• Integrate and leverage AI agents to increase velocity for the security team
• Lead security assessments and penetration testing of applications, AI services, and APIs
• Design and implement security controls for data pipelines, model training environments, and AI agents

Required qualifications

• 4+ years of hands-on experience in application security engineering
• Proven track record of securing large-scale production systems
• Understanding of developer experience and developer workflows
• Technical expertise in at least two programming languages (Python, Java, Go, JavaScript/TypeScript)
• Ability to read and review code across multiple languages
• Knowledge of security tools and methodologies including SAST/DAST solutions, vulnerability management platforms, security testing frameworks, and DevSecOps practices
• Excellent communication skills
• A builder's mindset

Nice to have

• Worked in fast-growing startups or high-growth environments

Benefits

• Generous PTO, plus company holidays
• Comprehensive medical and dental insurance
• Paid parental leave for all parents (16 weeks)
• Fertility and family planning support
• Competitive pension scheme and company contribution
• Wellness stipend for gym, massage/chiropractor, personal training, etc.
• Learning and development stipend
• Company-wide off-sites and team off-sites
• Competitive compensation and company stock options

About the company

WRITER is the AI platform built for the world’s most ambitious marketing and revenue teams. Founded in 2020, it is backed by investors including Insight Partners, Salesforce Ventures, and Adobe Ventures.