Senior App Security Engineer Remote UK Hands-on Ownership

OJ Digital; United Kingdom; Remote; GBP 165,000 - 225,000; Full time

Job summary

OJ Digital is seeking a Senior Application Security Engineer to own security across production products and to work closely with software and ML engineers to embed practical controls from the outset. The role is hands-on and involves shaping how AI agents access data, use tools and interact with external systems.

You will write code and build security automation with Python, Go or TypeScript, defending sensitive customer data while partnering with product and ML teams to turn security risks into

Qualifications

• 5+ years hands-on experience in application security or product security engineering.
• Experience securing production applications operating at scale.
• Proficiency in Python, Go or TypeScript for tooling and automation.
• Knowledge of OWASP Top 10, AuthN/AuthZ, secure SDLC and cryptography basics.
• Understanding agentic AI security at the product layer.
• Active coding background and ability to ship improvements with engineers.
• Confidence taking ownership in a fast-moving environment where processes are still being built.
• Familiarity with FedRAMP, HIPAA, SOC 2 or ISO 27001 would be beneficial.

Responsibilities

• Own application security across production products, including authentication, authorization, secrets management and secure integrations.
• Embed threat modeling, security code reviews and automated checks into development and release workflows.
• Define secure patterns for AI agents, covering permissions, tool access, trust boundaries and output validation.
• Build security tooling and automation using Python, Go or TypeScript.
• Protect sensitive customer data through access controls, secure handling patterns and audit logging.
• Partner with product and ML engineers to turn security risks into practical controls.
• Use AI tools to accelerate code analysis, threat modeling and security reviews.

Skills

Python

Go

TypeScript

Security tooling

Education

Computer Science degree or equivalent

Job description

OJ Digital is seeking a Senior Application Security Engineer to own security across production products and to work closely with software and ML engineers to embed practical controls from the outset. The role is hands-on and involves shaping how AI agents access data, use tools and interact with external systems.

You will write code and build security automation with Python, Go or TypeScript, defending sensitive customer data while partnering with product and ML teams to turn security risks into