System Administrator

Responsibilities:

• System Administration

  • Manage, monitor, and maintain Linux (RHEL, Ubuntu, CentOS) and Windows Server environments.
  • Perform system hardening, patching, and regular OS upgrades according to security best practices. (Linux and Windows Base)
  • Configure and optimize services such as Nginx, Apache, SSH, and system daemons.
  • Responsible for the day-to-day maintenance and management of Linux servers.

• Database Management

  • Administer and maintain MySQL or other databases, including security controls and monitoring alerts.

• Monitoring, Logging and backup

  • Deploy and manage ELK / OpenSearch Stack for centralized logging and analytics.
  • Integrate system and application logs for proactive monitoring and troubleshooting.
  • Create dashboards, alerts, and reports for operational visibility by Zabbix
  • Perform backup, restore, replication, and performance tuning. (Linux, Windows, DB)

• Security & SSL Management

  • Implement, renew, and troubleshoot SSL/TLS certificates for web servers and secure communications.
  • Support PKI and certificate lifecycle management (CSR generation, CA integration, CRL/OCSP handling).
  • Enforce access control, MFA, and system auditing aligned with compliance standards (e.g., PCI DSS, ISO 27001).

• Networking & Troubleshooting

  • Understand TCP/IP, routing, DNS, VLANs, Firewalls, VPNs, and load balancers.
  • Collaborate with network and security teams to ensure optimal connectivity and resilience.
  • Basic Diagnose and resolve network-related performance issues between systems and applications.

Qualifications & Skills

• Bachelor’s degree in Computer Engineering, Information Technology, or related field.
• 5+ years of experience in system administration or system engineering.
• Hands-on Experience and Technical Skills
• Proficient in Linux (RHEL, Ubuntu, Debian) service, software package, system, and security management.
• Proficient in server hardware installation, configuration, and lifecycle maintenance (RAID, firmware, diagnostics, remote management).
• Experienced in managing Nginx, Apache, and other web/proxy services, skilled in SSH hardening and access control.
• Experienced in Windows Server administration.
• Hands-on experience with VMware and basic Docker/Containerd environments.
• Security & Certificates: Deep understanding of SSL/TLS lifecycle management.
• Hands-on experience with ELK/OpenSearch Stack for centralized logging, monitoring, and visualization.
• Skilled in MySQL Database Administration or Others Database.
• Understanding of TCP/IP, VLAN, routing, NAT, VPN (IPsec/SSL), and Firewall/Load-balancing concepts.
• Experienced in designing and maintaining backup, disaster recovery, and high-availability strategies.
• Familiar with CIS Benchmarks, PCI DSS v4.0, ISO 27001, and audit documentation preparation.

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Personal Attributes

• Proactive, detail-oriented, and passionate about automation and operational excellence.
• Able to work independently and collaboratively in cross-functional technical teams.
• Strong problem-solving mindset with a focus on security, performance, and reliability.

Work location: Near BTS Chong nonsi

Thai Payment Network Co.,Ltd.
173/19 Asia Centre Building 18th Floor, South Sathorn Road,
Thungmahamek Sub-District,  Sathorn District, Bangkok 10120