Booking Holdings Romania - Senior Cybersecurity Incident Responder, Enterprise Security

Booking Holdings Romania is a Center of Excellence based in Bucharest, Romania and was created to support the increasing business demands of the Booking Holdings Brands. The Center of Excellence provides access to specialized and highly skilled talent, leading industry best practices, and collaboration opportunities across all of our Brands.

As part of our Booking Holdings Romania team, you will have the opportunity to be a part of the world’s leading provider of online travel, with a mission of making it easier for everyone to experience the world through five-primary consumer facing brands: Booking.com, Priceline, Agoda, KAYAK and OpenTable.

This role provides a hybrid way of working with an onsite presence of 2 days/week.

Role description

The Senior Cyber Security Incident Responder is a key player in providing in-depth investigation and response to cyber security attacks and threats such as ransomware, spear-phishing, cloud-based or supply chain attacks, and Advanced Persistent Threats (APTs).

This highly specialized technical subject matter expert position focuses on investigating threats and alerts within large-scale cross-platform environments, performing threat hunting and digital forensics in order to identify intrusions and effectively respond to mitigate security threats on the business.

Key Job Responsibilities and Duties

• Investigate and validate incidents escalated by the BKNG CDR team (assessing escalation, evidence completeness, and initial hypothesis). • Lead complex security investigations end-to-end, from initial triage through containment, eradication, recovery, and post-incident review. • Act or support the incident lead or incident commander for high-priority and high-severity incidents.. • Coordinates incident, response, escalation, and reporting of cybersecurity incidents. • Performs technical investigation on complex security incidents to achieve efficient mitigation for active threats and identification of the root cause. • Perform hands-on log analysis, endpoint forensics, identity investigation, cloud investigation, email investigation, network analysis. • Investigate and respond to AI/LLM-specific incidents (prompt injection, model or agent misuse, AI sandbox escapes, AI supply chain risks). • Contribute to emerging AI threat detection and response (AIDR) playbooks and readiness. • Collaborates on various departmental projects that help the organization improve its cyber security posture and achieve its mission/objectives. • Collaborates with different CDR stakeholders and vendors to remediate any identified gaps. • Define and use CSIRT’s playbooks, runbooks, workflows, operational documentation, and processes. Contributes to the writing and maintenance of all such documents. • Looks for opportunities to improve documentation and standardization of CSIRT processes. • Owns and delivers on assigned projects (often around automations, AI usage, and improvements to detections, processes and playbooks) while balancing execution and deliveries with operations and IR workload; Supports other team members in projects. • Identify detection gaps, false positive drivers, visibility gaps, and automation opportunities based on investigation findings. • Contribute to the design and improvement of detection rules, workflows, and operational automation. • Drive threat hunting to proactively identify threats and validate detection coverage. • Participate in tabletop exercises, retrospectives, lessons-learned sessions, and service improvement initiatives. • Mentor and technically guide other analysts: improving investigation quality, structure, and consistency across the team • Review investigation work and escalation packages for quality and completeness. • Share knowledge through team & community sessions, written documentation, and informal coaching. • Works on shifts covering 16/5 (Monday to Friday, 7 AM - 10 PM). • Offers on-call support during the nights, weekends and public holidays.