Madrid, Community of Madrid, Spain
Cybersecurity researcher, published author, and GNU/Linux systems engineer with 20+ years defending digital freedom and building secure systems. I specialize in offensive security research, penetration testing, and developing privacy-preserving technologies. My work spans from low-level systems programming to architecting secure cloud infrastructures, always prioritizing Free/Libre Open Source Software principles. **Recent Highlights:** • Published "Connection Timeout: The PingStarved Chronicles" (2025) - A tech-thriller exploring mesh networking, surveillance resistance, and hacker culture • Hacking Capture the Flag competitions player when time permits • Contributing to decentralized communication protocols and mesh networking implementations **Technical Focus:** • Offensive Security: Ethical hacking, penetration testing, red teaming, exploit development • DevSecOps: Security automation, CI/CD pipeline hardening, infrastructure as code, shift-left security • Systems Programming: C/C++, Rust, Assembly (x86_64), kernel-level development • DevOps & Cloud: AWS, Kubernetes, Docker, Terraform, zero-trust architectures • Privacy Tech: Mesh networks (Meshtastic, Reticulum), encrypted communications, anti-surveillance tools **Development:** Currently working with Rust for security tools, Ruby/Rails for rapid prototyping, and diving deep into x86_64 assembly for exploit research. Always exploring emerging languages and frameworks that advance security and privacy. I believe technology should liberate, not subjugate. Every line of code is a political act, and I choose to write mine in service of digital freedom. **Find Me:** 📚 Author Page: https://www.amazon.com/stores/author/B0FQ742DBW/about 🎯 Hack The Box: https://www.hackthebox.eu/profile/16000 💼 Toptal Profile: https://www.toptal.com/resume/christian-fernandez 🐘 Mastodon: @[email protected] Note: I rarely check LinkedIn for privacy reasons. For faster responses, please contact me at [email protected] or Signal: rek.02 #InfoSec #EthicalHacking #DevSecOps #DevOps #OffensiveSecurity #FOSS #Privacy #CyberSecurity #PenetrationTesting #Linux #CloudSecurity #hacking #CTF
The World's Top Talent, On Demand they find me clients looking for top talent freelancers with my skills. If you like me to do some temp/hourly work for you check https://www.toptal.com/resume/christian-fernandez
https://www.upwork.com/fl/christianfernandez Reconnaissance Scanning Exploitation write documentation with findings.. offer to fix/help with solutions like configuring iptables/firewalls, ids/snort, vulnerable software, write security policies.. etc
Job entitles a strong background in "ethical hacking" and linux/systems engineering, that can elevate our systems to an enterprise level of security. hands-on, and understand the theory behind the solutions implemented. Build and maintain all systems (and their security) in all levels (from workstation to production servers) and schedule audits and penetration tests in-house and by third parties . As the company grows, I will have the opportunity to build out my team. - Security: Responsible for day-to-day information security engineering. Enforcing best security practices at all levels: server, network, web application, data storage, access controls, etc. Developing and enforcing change management and managed access policies. Coordinating penetration tests. Staying on top of security advisories for systems in our stack and keeping systems updated with security patches as they are released. Ensuring that employee development environments and devices do not pose a security risk. Enjoying a highly collaborative environment, working closely with a team of engineers and others. - Systems Engineering: Setting up new servers, from configuring the ideal spec to selecting the services that will run, ensuring configurations are tracked and consistent across machines. Diagnosing and fixing scaling and reliability issues. Identifying bottlenecks preventing more efficient resource utilization at the system level. Monitoring, managing and configuring MySQL replication. Setting up and maintaining Continuous Integration systems.
Will fix this soon in the mean time: I am going to be using: Amazon Web Services Linux Containers and Virtualization (Docker, Kubernetes) Linux/UNIX administration TCP/IP Networking Information Security Practices configuration management & automation (ie. Saltstack, Ansible or Chef) Infrastructure as code (Cloud Formation/Terraform) Software Development Life Cycle, Continuous Integration and Continuous Delivery working with high availability, high performance, multi-data center systems Agile methodologies and working closely within small teams version control systems (Git) Monitoring and Metrics Gathering (CloudWatch, DataDog, Nagios) Scripting (ie. Bash, Python or Ruby) etc.
Setting up, securing, configuring and maintaining our AWS based infrastructure for development, ,staging and production. Developing automated build, configuration, and deployment scripts for servers, open source software and our own proprietary software. Ensuring that our solutions are secure, manageable, scalable, and testable. Collaborating with our team, presenting my concepts and ideas, and driving the development Ongoing system monitoring and management activities Evaluating and recommending the use of tools and technologies. At the moment finishing a architecture revamp, to follow up with a full security examination and configuration.