Application Security Engineer
Booking.com1 day ago
Amsterdam, NetherlandsMid Level / Senior
Responsibilities
- Build, operate, and improve WAF protections for internet-facing applications and APIs, including managed rules, custom rules, rate limits, and exceptions.
- Manage security changes through CDK and delivery pipelines with review, validation, rollout monitoring, and rollback planning.
- Tune edge controls to reduce application-layer exposure while managing false positives and service impact.
- Use WAF, SIEM, application, and cloud telemetry to create or improve detection logic, queries, alert context, and investigation playbooks.
- Provide third-line technical escalation for application security incidents, including triage, scoping, evidence preservation, containment coordination, and documentation.
- Recommend and implement improvements to WAF policies, detections, logging, runbooks, and automation based on incident findings.
- Write and maintain scripts or small tools that improve security operations, WAF changes, investigations, and response workflows.
- Coordinate with application, platform, security operations, and incident response partners, and support junior colleagues with established tasks.
Requirements
- Approximately 3–5 years of experience in security engineering, application security, cloud security, detection and response, or a closely related hands-on role.
- A relevant bachelor’s degree or equivalent practical experience.
- Practical experience designing, operating, or tuning web application firewall controls; AWS WAF experience is strongly preferred.
- Experience managing security configuration through code and delivery pipelines, with working knowledge of infrastructure as code and safe change practices.
- Ability to investigate web and API activity using SIEM or log analytics tools, formulate queries, correlate events, and assess alert quality.
- Working knowledge of HTTP, web applications, APIs, application-layer attack patterns, and edge-based mitigation controls.
- Hands-on scripting or programming experience in Python, TypeScript, JavaScript, or a comparable language.
- Experience participating in security incident investigations, including triage, scoping, evidence gathering, containment coordination, and documentation.
- Clear communication, sound judgment, independent execution of common tasks, and willingness to seek support for unusual or complex situations.
- Preferred qualifications include AWS security and logging experience, WAF log analysis, cloud-native application experience, SIEM detection engineering, alert tuning, incident playbooks, security automation, OWASP web and API risk knowledge, bot-abuse mitigation, and version control or code review experience.
Benefits
- Annual paid time off and generous paid leave, including parent, grandparent, bereavement, and care leave.
- Hybrid working with flexible arrangements and up to 20 days per year working from abroad in the home country.
- Booking.com product discounts of up to 1400 per year, including automatic Genius Level 3 status and wallet credit.
- Opportunity to work on a large-scale product used by millions of travelers and participate in technical development activities such as conferences, hackathons, and community programs.
- The role is based in Amsterdam and does not come with relocation assistance.
Tech Stack
Categories
About Booking.com
Booking.com operates a global online travel platform for booking accommodations, flights, car rentals, and experiences for consumers and business travelers. It earns primarily through commissions and merchant/agency models with hotels, vacation rentals, and other travel partners. Founded in 1996 and headquartered in Amsterdam, it is part of Booking Holdings and serves users and suppliers across hundreds of markets worldwide.