Senior WAF Engineer, Autonomous Defense

The role

You will act as the blue team voice within the Firewall team to define correct remediation for detected attack techniques. You will partner with Product and Engineering to translate blue team workflows into product requirements and validate releases.

What you will do

• Partner with Product to turn WAF effectiveness and tuning ambitions into concrete, buildable requirements.
• Translate blue team workflows and pain into prioritized product outcomes.
• Define acceptance criteria for detection, effectiveness, and tuning features.
• Validate releases against acceptance criteria before customers see them.
• Serve as the standing domain reference for Engineering and AI research.
• Own deep, current knowledge of major WAF platforms.
• Maintain fluency in how rule evaluation and enforcement work in each product.
• Define vendor-specific rule semantics.
• Track platform releases, rule and API changes, and vendor guidance.
• Define what a correct WAF tuning recommendation looks like.

Required qualifications

• 5+ years in application security, security engineering, security operations, incident response, or threat hunting.
• 2+ years of hands-on experience administering and tuning WAF platforms in production.
• Hands-on experience administering and tuning WAF platforms (AWS WAF, Cloudflare WAF, F5 Advanced WAF, Imperva, Akamai App & API Protector, FortiWeb, or ModSecurity with OWASP CRS).
• Deep understanding of how AppSec and SOC teams use WAF rule outcomes and request logs.
• Fluency in false-positive and false-negative tradeoffs, overly permissive rules and exclusions, and application-availability risks.
• Strong working knowledge of the OWASP Top 10 and MITRE ATT&CK.
• Solid understanding of web attack behavior in HTTP requests and WAF telemetry.
• Demonstrated experience shaping a product or platform as a domain expert.
• Ability to influence without authority.
• Exceptional technical writing.
• Ability to translate between engineers, AI researchers, product managers, SOC analysts, and executives.
• Scripting ability, ideally Python, to query APIs, inspect telemetry, and prototype an analysis.

Nice to have

• Python

Benefits

• Equity package in the form of stock options
• Health, vision & dental insurance for you and your family
• Flexible vacation policy
• Generous parental leave

About the company

Horizon3 is a fast-growing, remote cybersecurity company dedicated to enabling organizations to proactively find, fix and verify exploitable attack vectors. The team is a fusion of former U.S. Special Operations cyber operators, startup engineers, and cybersecurity practitioners.