Network Security Engineer (Lisbon)

Cloudflare, Inc.; Lisboa; On-site; EUR 38,000 - 52,000; Full time

Benefits offered by this job

Equity plan

Job summary

Cloudflare, Inc. in Lisbon, Portugal is seeking an experienced Network Security Engineer to join our team and support large, technically sophisticated customers.

You will resolve threats and attacks on infrastructure across OSI layers 3, 4, and 7, using Cloudflare products from Magic Transit to WAF, and collaborate with engineering and product teams. The role demands a strong background in networking, DNS, TCP/IP, and scripting.

Qualifications

• Self-driven with the ability to learn new technologies with little guidance.
• Fundamental understanding of 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 with web servers such as 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 to determine good vs malicious traffic.
• DDoS mitigation for OSI layers 3,4, & 7 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 and apply the appropriate mitigation.
• Work with Engineering and Product teams to improve the products and tools.

Skills

OSI Model

TCP/IP

Networking basics

iptables

DNS troubleshooting

BGP routing

GRE tunnels

Bash scripting

Python

JavaScript

Customer facing

CLI tools

Tools

curl

dig

traceroute

openssl

git

Apache

Nginx

Caddy

IIS

PostgreSQL

MySQL

SQL Server

Job description

Cloudflare, Inc. in Lisbon, Portugal is seeking an experienced Network Security Engineer to join our team and support large, technically sophisticated customers.

You will resolve threats and attacks on infrastructure across OSI layers 3, 4, and 7, using Cloudflare products from Magic Transit to WAF, and collaborate with engineering and product teams. The role demands a strong background in networking, DNS, TCP/IP, and scripting.