Senior Application Security Engineer in London

About Triple Lift

We're Triple Lift, an advertising platform on a mission to elevate digital advertising through beautiful creative, quality publishers, actionable data and smart targeting.

Through over 1 trillion monthly ad transactions, we help publishers and platforms monetize their businesses.

Our technology is where the world's leading brands find audiences across online video, connected television, display and native ads.

Brand and enterprise customers choose us because of our innovative solutions, premium formats, and supportive experts dedicated to maximizing their performance.

As part of the Vista Equity Partners portfolio, we are NMSDC certified, qualify for diverse spending goals and are committed to economic inclusion.

Find out how Triple Lift raises up the programmatic ecosystem at triplelift. com .

Overview

The Senior Application Security Engineer plays a critical role in driving secure software development and application security maturity within Triple Lift's Engineering and Security organization, directly influencing how we protect our advertising platforms and the trust our publishers and advertisers place in us.

In this position, you will partner closely with Engineering, Platform, Cloud Infrastructure, and Security teams to shape secure coding practices, application security tooling, vulnerability remediation, and CI/CD security, ensuring security is embedded into how we design, build, deploy, and operate our products.

This is an exciting opportunity for someone who wants to build and scale an application security program at a company operating at the center of a rapidly evolving, high-stakes ad-tech landscape, while contributing meaningfully to the long-term security posture and resilience of the organization.

Responsibilities

• Play a critical role in building and maintaining a global security compliance program based on NIST CSF.
• Scale application security by developing automated security testing utilizing enterprise SAST, DAST, and code-review tools.
• Champion SDLC to promote secure application development and infrastructure deployment and facilitate secure coding remediation activities.
• Automate security testing in CI/CD pipelines to detect vulnerabilities early, including building and maintaining the pipeline integrations themselves.
• Administer and drive adoption of Git Hub Advanced Security (GHAS) : code scanning, secret scanning, and dependency review across engineering repositories.
• Participate in threat modeling and design/architecture spec reviews to identify and mitigate security risks early in the SDLC.
• Coordinate with stakeholders to develop and implement a vulnerability management program and to perform threat-hunting activities.
• Own and conduct internal penetration testing and vulnerability assessments of applications and infrastructure, and validate findings from third-party pentest engagements.
• Monitor and respond to application-layer security threats like API abuses, business logic flaws, and common web vulnerabilities.
• Collaborate with product and engineering teams to ensure security is a key consideration in software design and architecture.
• Enhance application security posture by working with cross-functional teams to implement proper authentication, authorization, and data protection mechanisms.
• Enhance and facilitate security incident handling activities.
• Evangelize security best practices and provide education and awareness to company employees.

Develop and implement secure coding guidelines and conduct secure development training for engineers.

• Evaluate and continuously improve the maturity of the security program through the deployment and management of various security tools and processes.

Education & Requirements

• 5+ years of experience in application security, secure software development, security engineering, or a similar role.
• Strong understanding of secure coding practices and ability to guide developers on remediation strategies.
• Experience with Git Hub Advanced Security (GHAS), including Code Scanning (SAST), Secret Scanning, and Dependency Review.
• Proficiency in SAST, DAST, and SCA tools (e. g., Code QL, Burp Suite, OWASP ZAP, Snyk, Checkmarx, Veracode).
• Hands-on experience integrating security testing tools into CI/CD pipelines for automated security scanning, including designing and building pipeline workflows.
• Hands-on penetration testing / offensive security experience across web applications, APIs, or cloud infrastructure.
• Knowledge of common application security vulnerabilities and mitigations (OWASP Top 10, CWE, business logic flaws, API security).
• Ability to perform threat modeling and participate in design/architecture spec reviews to assess security risks in applications and services.
• Experience conducting security code reviews across various programming languages (e. g., Python, Java, Type Script, Go).
• Understanding of security fundamentals with relation to various cybersecurity and compliance frameworks, particularly NIST CSF, but any of PCI, SOC2, HITRUST, ISO 27001/2, or similar.
• Strong understanding of AWS security services and controls (IAM, VPC, KMS, Guard Duty, Cloud Trail) and experience securing cloud-native environments and workloads, with the ability to deploy security tools within them.
• Takes ownership of projects, works independently with minimal oversight, and delivers results in a fast-paced environment while balancing multiple priorities.
• Continuously learns, adapts, and values correctness, efficiency, and constructive feedback.

Preferred

• Experience in the ad-tech / programmatic advertising industry, or another high-scale, real-time environment.
• Preferred: Familiarity with using AI/LLM-based tools (e. g., Claude or similar) for threat intelligence, alert triage, or security automation.
• Holds a cybersecurity certification, e. g., OSCP, GWAPT, CISSP, CISA, etc.

US Jobs

The base salary range represents the low and high end of the Triple Lift US salary range for this position.

Actual salaries will vary depending on factors including but not limited to experience and performance.

The range listed is just one component of Triple Lift’s total compensation package for employees.

Other rewards may include bonuses, an open Paid Time Off policy, and many region-specific benefits.

Pay is based on various non-discriminatory factors including but not limited to experience, education, and skills.

Benefits Available to Eligible Employees Include the following*

• Medical, Dental & Vision Plans
• Flexible PTO
• 401k w/ employer match

*Full-time employees are eligible for comprehensive benefits (subject to the terms of applicable plans/policies/agreements, which will be made available to you after commencing employment).

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• $125,000
• $165,000
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We want to ensure the best talent of every background, viewpoint, and experience has an opportunity to be hired, belong, and develop at Triple Lift.

Through our People, Culture, and Community initiatives, we aim to create an environment where everyone can thrive and feel a true sense of belonging.

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