Location
London

Hours
Full Time

Salary
Negotiable

About the Role
Meta's Security Engineering team is seeking a Security Engineer to help protect billions of users and Meta's global infrastructure from evolving threats. In this role, you will conduct security assessments, vulnerability research, and threat modeling across Meta's products and systems — spanning mobile applications, web platforms, backend services, and internal infrastructure. You will identify systemic security gaps, drive mitigations at scale, and partner with engineering teams to embed security best practices into the software development lifecycle. Your work will directly reduce risk for Meta and its users by turning one-off security findings into durable, scalable defenses.

Key responsibilities include conducting security assessments, penetration testing, and vulnerability research across Meta's web, mobile, and backend systems to identify and remediate security risks; performing threat modeling and security architecture reviews for new and existing products and infrastructure; identifying systemic security gaps and driving cross-functional mitigations that scale beyond individual findings; developing and improving security tooling, automation, and detection capabilities to enhance the team's ability to identify and respond to threats; collaborating with product and infrastructure engineering teams to define security requirements and integrate security controls into the software development lifecycle; leading complex security investigations and incident response efforts, coordinating with cross-functional partners to resolve issues and prevent recurrence; translating security findings into actionable, prioritized recommendations for engineering and leadership audiences through clear written documentation; mentoring other engineers on security best practices; supporting recruiting and onboarding efforts; managing on-call security responsibilities independently; and identifying and landing new security initiatives on the team roadmap that address high-complexity, ambiguous risk areas aligned with broader team strategy.

Experience
- 6+ years of experience in security engineering, including hands-on work in penetration testing, vulnerability research, or security assessments of web, mobile, or backend systems
- Experience performing threat modeling and security architecture reviews for large-scale software systems
- Experience identifying systemic security risks and driving cross-functional remediation efforts that result in scalable, durable improvements
- Experience developing or improving security tooling, automation, or detection capabilities to support team-level security operations
- Experience communicating security findings and risk assessments in writing to both technical and non-technical stakeholders
- Experience with security automation, static or dynamic analysis tooling, or building internal security platforms
- Familiarity with security considerations specific to large-scale distributed systems, mobile platforms (iOS or Android), or cloud infrastructure
- Experience with offensive security techniques including exploit development, binary analysis, or red team operations
- Proficiency in one or more programming or scripting languages (e.g., Python, C/C++, Java) used to develop security tools or analyze vulnerabilities
- Demonstrated ability to integrate AI tools to optimize/redesign workflows and drive measurable impact (e.g., efficiency gains, quality improvements)
- Demonstrated ongoing AI skill development (e.g., prompt/context engineering, agent orchestration) and staying current with emerging AI technologies
- Experience adhering to and implementing responsible, ethical AI practices (e.g., risk assessment, bias mitigation, quality and accuracy reviews)

About you
You are a proactive and detail-oriented security professional with a passion for protecting complex systems at scale. You thrive in collaborative environments and are skilled at translating complex security concepts into clear, actionable guidance. You are committed to continuous learning, especially in emerging AI technologies and ethical AI practices, and you take initiative to lead new security projects that address ambiguous and high-impact risks.

Qualifications
Relevant degree or equivalent experience in computer science, cybersecurity, or related fields is preferred but not mandatory. Proven track record of hands-on security engineering and leadership in complex environments is essential.