Web Security Threat Hunter & Detection Researcher

Cloudflare; United Kingdom; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Stock options

Flexible vacation

Parental leave

Healthcare

Life insurance

Disability insurance

Pension plan

Commuter benefits

Wellbeing programs

Job summary

Cloudflare is seeking a security-focused engineer to join our Detection team in the UK. You will work on detecting automated and malicious activity at scale, reverse engineering attacker techniques, and translating insights into actionable signals used across products.

The role emphasizes scripting in Python/JavaScript and collaboration with product and data science teams. You will contribute to scalable detections, mitigations, and automation, helping to stay ahead of evolving threat landscapes

Qualifications

• Love for ethical hacking and reverse engineering with an adversarial mindset.
• Proficiency in Python and JavaScript for proofs-of-concept and tooling.
• Deep web expertise across HTTP, TLS, browser internals, and evasion techniques.
• Strong communication to explain attacker behavior to varied audiences.

Responsibilities

• Translate attacker behavior into concrete detection signals.
• Develop heuristics, signatures, and detection ideas with Data Scientists and Engineers.
• Automate manual investigations and rule-writing into scalable tooling.
• Design mitigations that preserve signals while neutralizing attackers.

Skills

Python

JavaScript

Ethical hacking

Reverse engineering

Adversarial mindset

Detections signals

HTTP/TLS

Fingerprinting

CAPTCHAs

Job description

Cloudflare is seeking a security-focused engineer to join our Detection team in the UK. You will work on detecting automated and malicious activity at scale, reverse engineering attacker techniques, and translating insights into actionable signals used across products.

The role emphasizes scripting in Python/JavaScript and collaboration with product and data science teams. You will contribute to scalable detections, mitigations, and automation, helping to stay ahead of evolving threat landscapes