Senior Penetration Tester

Apply here to our career site : https://www.bookingholdings-coe.com/bookingholdings-coe/jobs/30080?lang=en-us&iis=LinkedIn&iisn=Linkedin&mode=apply

Role Description

The Senior Penetration Tester defines and leads the execution of highly technical and specialized engagements and designs new techniques of testing based on the evolution of industry best practices over time, including emerging areas such as AI and machine learningdriven systems.

They are both performing hands-on technical testing without requiring supervision and are coordinating teams of testers to ensure that the engagement objectives are met. They strengthen Bookings security posture by proactively identifying vulnerabilities and security control gaps in our systems and applications. The Senior Penetration Tester provides critical input to the Senior Manager - Threat Management with the development of the security assurance strategic plan based on subject matter expertise to increase the impact and value added through this area of focus.

The Senior Penetration Tester also helps further grow the security assurance area by mentoring other team members and members of other technical non-pentester communities within Booking. The Senior Penetration Tester has strong stakeholder management skills that enable effective communication of technical information to multi-level (up to CISO/CSO level), technical and non-technical audiences both within Booking and the broader Booking Holdings organization.

Key Responsibilities

Defines and leads the execution of highly technical penetration tests and security assurance engagements that deliver value to Booking by independently performing hands-on, detailed technical tests without requiring supervision.

Owns the design of new technical testing engagements to best serve the current and future needs of the organization, being able to adapt industry best practices to the local technical and cultural environment.

Owns the responsibility to ensure that the budget allocated to pentesting activities performed by external vendors, delivers the necessary value and results in a good return on investment.

Actively contributes to the mid- and long-term security assurance strategic plan definition by introducing domain expertise insights and ensuring the plan is effective and impactful.

Grows the security assurance area of focus within security by understanding the current and target security posture of the business and identifying the skills and resources needed to effectively deliver on those needs.

Mentors junior and core penetration testers, driving their career growth within this highly specialized technical craft.

Provides deep technical expertise to the business in the following highly specialized domains:

Threat modeling

Web application / API penetration Testing

Mobile application penetration testing

Infrastructure and cloud penetration testing

Purple team assessments

AI/ML-powered systems (including LLMs and AI-assisted developer tooling), identifying and exploiting AI-specific threats such as prompt injection, data poisoning, and model abuse.

Provides guidance and recommendations to teams, taking into account the current state of their technical environment, their future roadmap and strategy, and the risk associated with the underlying findings and vulnerabilities.

Keeps up to date with the latest developments in vulnerabilities and threats within their domain of expertise, including AI/ML-related attack techniques, using this to assess the security posture of Booking to new trends and attacks

Drives and coordinates multi-disciplined teams (including internal testers, external contractors, engagement managers) to conduct and successfully deliver pentest engagements of booking systems and services.

Drives the reporting of penetration test outcomes by drafting, disseminating, and presenting them to technical and non-technical stakeholders at multiple levels (junior analyst to leadership team).

Collaborates and coordinates with cross-functional technical and non-technical stakeholders within Booking.com and Booking Holdings to achieve a successful testing engagement that delivers critical security value.

Supports the cross-brand security assurance program throughout Booking Holdings by engaging with key security personnel (CISOs to engineers)

Mentors and trains non-pentesters, such as developers and other technical roles, in the relevant aspects of penetration testing and vulnerability identification to scale their impact across the department and booking.

Requirements of special knowledge/skills Required:

Threat Modeling

2-3 years of threat modeling experience. Familiarity with threat modeling methodologies such as STRIDE or PASTA Web application / API Penetration Testing

Expert level understanding of application security concepts at both technical and procedural level

Expert level understanding and exploitation skills for web application vulnerabilities (OWASP - SQLi, XSS, CSRF, XXE, IDOR, SSRF, etc )

Expertise on at least one of the following DAST tools (AppScan, BurpSuite, Acunetix, Web Inspect, etc)

Experience of creating attack trees/chains

Experience of automating penetration testing tasks such as import API spec ( Swagger, Open API, etc ) to pentesting tools

Understanding (technical aspects of) penetration testing and results (including scoping and organizing of pentests, use of vulnerability scanners, vulnerability management tools) Secure SDLC

Good understanding of application security tooling integration with CI/CD pipelines of applications

Good understanding of how git works, good to have experience of Gitlab CI/CD

Ability to read code (Perl, Java, JS) and identify vulnerabilities

Ability to provide remediation recommendations to developers

Infrastructure and Cloud Penetration Testing

3+ years experience of performing penetration tests for infrastructure and network

Good understanding of kubernetes and virtualization technologies

Expert level understanding of vulnerabilities and exploitation techniques such as RCE, buffer overflows, subdomain takeover, dns exfiltration, privilege escalation, etc)

Hands on security experience of performing cloud security reviews for at least one of the following cloud platforms ( AWS, GCP, Azure ), AI / ML Security

Hands-on experience assessing the security of AI/ML systems (including LLMs or AI-based features), with exposure to threats such as prompt injection, data poisoning, model exfiltration, and abuse of model-integrated tools and plugins

Understanding of how AI/ML components integrate into web, mobile, and backend

architectures, and how to adapt existing security testing methodologies to cover these assets

Ability to translate AI-specific vulnerabilities into clear business risk and remediation guidance for product, data science, and platform teams

Manage Penetration Testing Lab

Experience of creating and managing penetration testing lab/infrastructure

Desirable:

7+ years of experience in information security

5+ years of relevant hands-on experience in offensive security testing and engagement management

Expertise in at least one of the following areas: (Web) application security, infrastructure and cloud security, mobile security

Excellence in communicating business risk and remediation requirements from assessments

Excellent stakeholder management skills

Proficient in scripting languages such as Python, PowerShell, Bash, and Ruby.

Competent with testing frameworks and tools

Understanding of OWASP, the MITRE ATT&CK framework and the software development lifecycle (SDLC).

Analytical and problem-solving mindset.

Highly organized and efficient

Desirable:

Experience in offensive tactics

Software development experience

Experience with using tools such as Burp Suite, AppScan, Acunetix , Zap ,Web Inspect, Metasploit, Nessus / Qualys and OSINT tools

One or more of the following certifications: OSCP, OSCE, GPEN, GWAPT, CEH, CISSP or a similar recognized certification in their domain of expertise