Network Security Engineer

About Us At Cloudflare, we are on a mission to help build a better Internet. Today the company runs one of the world’s largest networks that powers millions of websites and other Internet properties for customers ranging from individual bloggers to SMBs to Fortune 500 companies. Cloudflare protects and accelerates any Internet application online without adding hardware, installing software, or changing a line of code. Internet properties powered by Cloudflare all have web traffic routed through its intelligent global network, which gets smarter with every request. As a result, they see significant improvement in performance and a decrease in spam and other attacks. Cloudflare was named to Entrepreneur Magazine’s Top Company Cultures list and ranked among the World’s Most Innovative Companies by Fast Company. At Cloudflare, we’re not looking for people who wait for a polished roadmap; we’re looking for the builders who see the cracks in the Internet that everyone else has simply learned to live with. We value candidates who have the instinct to spot a "normalized" problem and the AI-native curiosity to create a solution using the latest tools. Our culture is built on iteration, leveraging AI to ship faster today to make it better tomorrow, while ensuring that every improvement, no matter how small, is shared across the team to lift everyone up. If you’re the type of person who values curiosity over bureaucracy, and that AI is a partner in solving tough problems to keep the Internet moving forward, you’ll fit right in. Available Location: Singapore or Tokyo, Japan This position is open to experienced candidates, as well as fresh graduates who will be graduating in December 2026 or Jan 2027. About the Team The Cloudflare Customer Support Team solves complicated problems and answers technical questions via phone, email, chat and social media. Whether it is a Wordpress blogger using our services for free or a global Enterprise business with petabytes of web traffic, we are always eager to assist. We are the eyes and ears of Cloudflare, acting as the real-time voice of the customer to help communicate their needs and real-world use cases back to the rest of the company - for better service and future product development. What You'll Do Do you love solving complex technical issues and interacting with people? Are you passionate about providing premium-level support to customers and are a standout colleague? Cloudflare is seeking an experienced Network Security Engineer to join our team and support our largest and most technically sophisticated customers in resolving technical problems, threats or attacks on their infrastructure at OSI Layers 3, 4, and 7. This will span the range of Cloudflare products from Magic Transit Infrastructure Protection, Argo Smart Routing, DDoS mitigation and Network Firewall, to using the Web Application firewall (WAF), Spectrum and Rate Limiting to help customers. • Serve as a trusted technical advisor for our enterprise customers, responding to and resolving inquiries and incidents related to network security and performance, while delivering timely, high-quality and personalized assistance. • Work directly with customers to diagnose, troubleshoot and resolve complex technical issues involving DDoS mitigation, firewall rules, SSL/TLS, network confirmation, and other security configurations. • Create and maintain knowledge base articles, technical guides, and troubleshooting documentation for internal and customer use. • Compare traffic signatures and attributes including IP addresses, cookie variations, HTTP headers, and JavaScript footprints to determine what is good traffic and what is malicious • DDoS mitigation for OSI layers 3,4, & 7: advise customers on how to filter malicious traffic using Cloudflare tools like Magic Transit, Network Firewall, WAF, IP reputation lists, packet inspection, blocklisting, allowlisting, and rate limiting • Work with Engineering and Product teams to improve products and tools • Utilize generative AI and automation tools to streamline log analysis, accelerate root-cause analysis during security incidents, and optimize customer response times. What We're Looking For • You have a minimum of 4 years experience working as a Network Security Engineer / Technical Support Engineer / Sr. Support Engineer supporting networking or web security products. • Exceptional troubleshooting and problem-solving skills, with the ability to simplify complex concepts for customers. • Strong customer service orientation and communication skills • Ability to work independently and collaboratively in a fast-paced, dynamic environment. • Strong understanding of network protocols, including TCP/IP, DNS, HTTP/S, and BGP, with a particular focus on anycast routing concepts and implementation, as well as tools such as iptables and looking glass. • Proven experience troubleshooting network connectivity issues, BGP routing, and GRE tunnels, and performing packet capture analysis • Confident with command line and tools, including curl, dig, traceroute, openssl, git • Experience in a web development and / or hosting environment such as installing and configuring web servers like Apache, Nginx, Caddy and IIS. • You are competent at writing scripts in Bash, Python, JavaScript or other scripting languages. • You have worked with PostgreSQL, MySQL, MS SQL, and other database servers. • Bachelor’s degree in Computer Science, Cybersecurity, or a related field (or equivalent experience). • Relevant certifications such as CISSP, GCIA GCIH, GCFA, GCFE or equivalent. What Makes Cloudflare Special? We’re not just a highly ambitious, large-scale technology company. We’re a highly ambitious, large-scale technology company with a soul. Fundamental to our mission to help build a better Internet is protecting the free and open Internet. Project Galileo: Since 2014, we've equipped more than 2,400 journalism and civil society organizations in 111 count