Network Security Engineer

Available Locations: Lisbon, Portugal 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.
Examples of desirable skills, knowledge and experience

• Self-driven and capable of learning new technologies / systems / features with little guidance
• Fundamental understanding how the Internet works (OSI Model)
• Advanced understanding of modern internet protocols like TCP and UDP
• Computer Networking fundamentals, experience with iptables and looking glass
• Experience troubleshooting network connectivity issues, BGP routing, and GRE tunnels
• Packet capture analysis
• Experience in command line and tools, including curl, dig, traceroute, openssl, git
• Experience troubleshooting DNS, SSL / TLS, HTTP
• Experience in a web development and / or hosting environment such as installing and configuring web servers like Apache, Nginx, Caddy and IIS
• Experience writing scripts in Bash, Python, JavaScript or other scripting language
• Experience in working as part of a team in a customer-facing role

Responsibilities

• Communicate with customers via chat, email, and phone
• 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 Operations teams to mitigate attacks, suggest steps to mitigate, and apply the appropriate mitigation, when applicable
• Work with Engineering and Product teams to improve the products and tools

Bonus Points

• You are fluent in German, Japanese, French, Spanish, Portuguese, or Mandarin
• You have worked with PostgreSQL, MySQL, MS SQL, and other database servers
• You are familiar with Cloudflare and are actively using our platform