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Curriculum Vitae

Senior Linux SysAdmin & Infrastructure Engineer · DevSecOps, Web Servers & Troubleshooting

Percio Andrade Castelo Branco

Senior Linux SysAdmin & Infrastructure Engineer · DevSecOps, Web Servers & Troubleshooting

40 years old · Manaus/AM, Brazil Email: perciocastelo@gmail.com | contato@perciocastelo.com.br · Manaus/AM, Brazil WhatsApp: +55 92 99396-9394 LinkedIn: linkedin.com/in/percioandrade GitHub: github.com/sr00t3d

Professional Summary

Senior Linux Systems Administrator with over 10 years of hands-on experience in mission-critical infrastructure, web server maintenance, advanced troubleshooting, and continuous automation.

My career was forged in high-demand hosting and web infrastructure environments, progressing through Tier 2/3 technical support, Linux systems administration, and technical supervision at HostGator Latin America, followed by independent consulting and operational security.

Specialist in Linux administration and troubleshooting (Debian, RHEL, AlmaLinux), cPanel/WHM, DirectAdmin, Apache, Nginx, BIND9 DNS, Exim, Dovecot, networking, and firewalls. Hardening baselines enforcement, log forensics, and emergency incident containment. Operational workflow automation using Shell Script, Python, Ansible, and APIs to standardize environments and eliminate repetitive tasks.

Active hands-on delivery in DevSecOps and pipeline security: automated security gates (Trivy, Gitleaks, Semgrep), Docker containerization, and modern infrastructure. Enrolled in Cyber Defense degree and Implementing DevSecOps (LFS262) from the Linux Foundation, preparing for the LFCS certification.

Creator of open-source security and infrastructure projects (NEXUS, LinTriage, EncFind), using them as practical engineering labs for security automation and observability.

✉️ Contact: perciocastelo@gmail.com | contato@perciocastelo.com.br
🔗 LinkedIn: linkedin.com/in/percioandrade · 💻 GitHub: github.com/sr00t3d

Technical Skills

  • Linux Infrastructure & Control Panels (cPanel/WHM, DirectAdmin, HestiaCP, FastPanel, CloudLinux)
  • Tier 2/3 Troubleshooting, Crisis Recovery, Web (Apache, LiteSpeed, Nginx), MySQL & BIND9 DNS
  • Linux Hardening, WAF & Firewalls (CSF/LFD, Imunify360, ModSecurity, fail2ban, nftables)
  • Incident response, log forensics, malware/webshell containment, and disaster recovery
  • DevSecOps & Secure CI/CD (Docker, GitHub Actions, SAST/SCA Trivy/Gitleaks/Semgrep in the NEXUS project)
  • Automation with Bash and Python, Ansible, operational tooling, and technical documentation / Runbooks
  • Observability (Zabbix, Nagios), proactive monitoring, and high availability
  • Open-source security and audit tooling (LinTriage, EncFind, BindFilter)

Personal Competencies & Teamwork

  • Clear communication, technical mentoring, and continuous knowledge sharing
  • Zero technical ego: business-driven pragmatism that empowers developer workflows
  • Incident management under pressure, MTTR reduction, and blameless post-mortems
  • Culture of documentation, actionable runbooks, and eliminating knowledge silos
  • Lifelong learner mindset with hands-on focus on modern automation and AI

Professional Experience

L2 Support Analyst / Linux SysAdmin, JoinVix 06/2025 - Present

Daily Linux server administration across shared and dedicated infrastructure. Responsible for keeping services online, diagnosing complex system failures, and automating manual tasks with Ansible and Shell scripts.

  • Routine automation with Ansible and Bash/Shell for standardization, patching, and operational optimization.
  • Advanced troubleshooting of web, email, network, and OS issues through deep log and metrics analysis.
  • Capacity and resilience management with proactive monitoring and preventive maintenance.
  • Linux server hardening, permission management, and attack-surface reduction.
  • Incident response with detection, isolation, and containment of malware, webshells, and unauthorized access.
  • Automation for continuous integrity auditing and environment verification.
SysAdmin & SecOps Consultant, M3Solutions 11/2023 - 03/2025 (1 year 4 months)

Hands-on technical consulting in Linux architecture, automation, high availability, and operational security for corporate clients.

  • Architecture and deployment of BIND9 HA DNS clusters for resilience and low latency.
  • Migration, provisioning, and management of servers/web services in public and hybrid cloud.
  • Security audit scripts/utilities plus KB and operational process documentation.
  • Emergency post-breach response: analysis, malware/webshell removal, and mitigation rules for safe recovery.
Independent Infrastructure Consultant & Operations Management 09/2015 - 10/2023 (8 years 2 months)

Autonomous technical consulting in Linux/cPanel servers for corporate clients and hosting providers, alongside operational management of a family business.

  • Advanced consulting and support for dedicated and VPS environments (cPanel/WHM, DirectAdmin, Apache, Nginx, MySQL, BIND9).
  • Full migrations of servers, web applications, and mail accounts with data integrity and minimal downtime.
  • Emergency post-breach response: malware containment, webshell removal, and defensive server hardening.
  • Development of Bash and Python automation scripts for admin tasks, backups, and audit routines.
  • Commercial operations management and technical infrastructure oversight focused on business continuity.
Senior Technical Support Supervisor, HostGator Latin America 09/2014 - 08/2015 (1 year)

Technical leadership for large-scale web infrastructure support, process governance, operational automation, and quality metrics (NPS/QA).

  • JumpStart project: standardized flows and technical onboarding at scale for the WordPress product.
  • Security policies and Linux hardening baselines to reduce attack surface.
  • Bash automation for critical admin tasks and fewer manual failures.
  • Legal support on security incidents and curation of the institutional engineering wiki.
Mid-level Linux Systems Administrator, HostGator Latin America 03/2014 - 08/2014 (6 months)

Advanced large-scale Linux infrastructure administration focused on availability, scalability, security, and production stability.

  • N3 troubleshooting of complex OS, network, and web-service failures with root-cause fixes.
  • Observability with Zabbix and Nagios, metrics, and granular alerts for proactive mitigation.
  • Operational actions and automations that reduced MTTR and downtime in dedicated/multi-tenant environments.
  • Support for Apache, Nginx, Mail, DNS, and databases with optimization and stability baselines.
Junior Linux Systems Administrator, HostGator Latin America 02/2013 - 02/2014 (1 year)

Advanced Linux infrastructure support for dedicated servers and complex multi-tenant environments.

  • Investigation and recovery of production failures across web, database, and email services.
  • Root-cause analysis via system and service logs to prevent recurrence.
  • Initial hardening, permission audits, and resource optimization under load.
  • Hardware and process monitoring to detect bottlenecks early.
Linux Support Analyst, HostGator Latin America 10/2012 - 02/2013

Technical support on high-density Linux servers via SSH, including web ecosystems and cPanel/WHM.

  • Vulnerability mitigation through CSF/iptables firewall rules and access control.
  • Access-log auditing and proactive blocking of malicious traffic and resource abuse.
  • Troubleshooting Apache, Nginx, Mail, and DNS with focus on stability and security.
Technical Support Analyst (N1/N2), HostGator Latin America 11/2009 - 09/2011

Fast triage and resolution of large-scale operational incidents across hosting platforms.

  • Incidents involving cPanel/WHM, DNS, and email (SMTP/IMAP/POP3).
  • Advanced Knowledge Base articles that reduced MTTR and improved onboarding.
  • Connectivity diagnostics, basic routing, and FTP/email client configuration.
Head of IT, SEMESP 06/2007 - 08/2008

Public-sector IT leadership covering governance, compliance, administrative workflow automation, and local infrastructure support.

  • IT governance policies, asset inventory, and process documentation aligned to public guidelines.
  • Python and PHP utilities to automate administrative workflows.
  • Relational databases and Microsoft systems with backup and availability routines.

Featured Projects

  • Kagin & Nexus: Active Defense Ecosystem on Oracle Cloud (OCI) with Python telemetry agents (OSINT / WAF Resilience Validation) and Terraform/IaC provisioning.
  • Forensics and DNS: Utilities such as LinTriage (forensic collection and automated triage), EncFind (webshell scanner), cPanel HF, and BindFilter (BIND9 blocking).
  • AI & SaaS: SaaS platform engineering (Evolya) and optimized local deployment of open LLMs (Gemma) with ZRAM on Linux.

Education

  • Wyden, Technologist Degree in Cyber Defense (Expected: 2028)

Certifications & Courses

  • Currently studying: Implementing DevSecOps (LFS262) and LFCS (Linux Foundation)
  • Cybersecurity Bootcamp, Riachuelo (2026)
  • Google Cybersecurity Certificate, Google (2026)
  • Cybersecurity Specialist, Santander / Ada (2026)
  • CyberSec Essentials (LFC108), Linux Foundation (2025)
  • OWASP API Security Top 10, OWASP (2025)
  • ISO/IEC 27001 Security Associate, SkillFront (2024)
  • cPanel & WHM Sysadmin II, cPanel (2024)