Linux System Administrator

Senior Technical Content Writer

Domains.co.za is a leading domain registration and website hosting company based in Johannesburg. We offer a variety of online solutions to help SME and entrepreneurial sectors of the marketplace establish their presence on the web.

We are looking for an experienced, hands-on Linux System Administrator to join our technical team and take responsibility for the Linux infrastructure underpinning our domains, web hosting, and virtualization services.

This is a deeply technical, hands-on role. You will build, administer, secure, monitor, troubleshoot and repair production Linux servers and the services running on them. You will work directly on customer-affecting systems — web, mail, database, DNS, and virtualization — and you will be the person who diagnoses and resolves problems rather than the person who assigns them.

We are looking for a practitioner, not an administrator of process. We are a technical team with a short path between a problem and the person fixing it, and we need someone who is comfortable working that way: taking ownership of an issue, digging into it directly, and seeing it through. Candidates whose experience is primarily in coordinating, reporting on, or managing technical work through organizational structures rather than performing it themselves are unlikely to be a fit for this role.

You will work with the support, network, and infrastructure teams to resolve escalations, improve platform stability, and continually harden and optimize our environment.

Job Level: Linux System Administrator (Senior)

Cost to Company: Market related

Work Arrangement: Hybrid

Job Description / Responsibilities

• Build, configure, administer, and maintain production Linux servers across the hosting, mail, database, DNS, and virtualization estate
• Diagnose, troubleshoot, and repair Linux server and service faults, from initial symptom through to root cause and permanent fix
• Administer cPanel and WHM environments — account provisioning, packages, resource limits, migrations, backups, and restores
• Administer and tune web servers (Apache, LiteSpeed), including virtual hosts, caching, PHP handlers, and performance optimization
• Configure, tune, and maintain ModSecurity rulesets, balancing protection against false positives on customer sites
• Administer mail infrastructure (Exim, Dovecot) — queue management, routing, authentication (SPF, DKIM, DMARC), deliverability, blacklist remediation, and anti-spam
• Administer MariaDB — configuration, tuning, replication, backups, restores, query performance troubleshooting, and repair of corrupted databases
• Administer domains and DNS at scale — zone management, delegation, records, propagation issues, DNSSEC signing and key management, and resolver troubleshooting
• Support and troubleshoot customer web applications, including WordPress, Magento, and WooCommerce — performance, compatibility, breakage after updates, and malware cleanup
• Support PHP and Node.js applications and runtime environments, including version management, extensions, and debugging application-level faults
• Implement, maintain, and troubleshoot security controls — firewalls or equivalent, SSH hardening, patching, kernel updates, intrusion detection, and vulnerability remediation
• Investigate and remediate compromised accounts and servers, including malware removal, and identify and close the entry point
• Configure and troubleshoot network components relevant to the hosting environment, including VLANs, routing, OSPF, and BGP sessions
• Manage and troubleshoot physical server hardware — provisioning, RAID and disk failures, memory and controller faults, IPMI/out-of-band management, firmware.
• Maintain and verify backup and disaster recovery processes, including regular restore testing
• Monitor platform health and capacity, respond to alerts, and identify and address issues before they affect customers
• Respond to and resolve escalations from the support team, with clear technical communication back to them and to customers where required
• Participate in incident response — restore service, then document root cause and the corrective actions taken
• Maintain accurate technical documentation, runbooks, and configuration records
• Be available on standby after hours for incidents and respond to them
• Identify and recommend improvements to platform stability, security, performance, and automation
• Keep current with Linux, hosting, virtualization, and security developments relevant to the environment

Technical Proficiencies

Proficiency and practical, hands-on work experience in:

• Apache
• LiteSpeed
• ModSecurity
• Exim
• Dovecot
• MariaDB administration
• cPanel / WHM
• KVM virtualisation
• PHP coding and PHP applications
• Bash scripting
• Node.js
• VLANs
• OSPF
• BGP
• DNS / DNSSEC

Skills and Experience

• 10+ years Linux experience
• 10+ years' experience in Linux server administration and troubleshooting
• 5+ years' experience in domains, web hosting, and virtualization
• Strong knowledge and proven experience in Linux server administration, troubleshooting, and repair
• Strong working knowledge of web hosting and cPanel administration
• Strong knowledge in implementing and troubleshooting web applications such as WordPress, Magento, and WooCommerce
• Strong knowledge and understanding of virtualization and KVM virtualized environments
• Strong knowledge and experience in domains and DNS administration
• Strong knowledge and understanding of internet services, security, and firewalls
• Strong knowledge and experience in server hardware management and troubleshooting
• Strong diagnostic ability — able to work from symptom to root cause methodically under pressure, on unfamiliar systems, with incomplete information
• Ability to work autonomously, take ownership of problems end to end, and see them through without supervision
• Sound judgement on risk and change on production systems, and the discipline to document what was changed and why
• Ability to communicate technical detail clearly to non-technical colleagues and customers
• Willingness to be on standby after hours for incidents and respond to them
• Valid driver's licence and own transport (advantageous, for data centre attendance)

Education / Qualifications

• Relevant IT qualification, or equivalent demonstrable hands-on experience
• cPanel University Certified (advantage)
• Linux certifications such as RHCSA, RHCE, LFCS, or LPIC (advantage)
• Networking certifications relevant to routing and switching (advantage)
• Continuous learning/training

Selection Process

Shortlisted candidates will complete a practical technical assessment on live systems, covering diagnosis and repair of faults across the web, mail, database, DNS, and virtualization stack. The assessment is weighted more heavily than the interview.

Disclaimer

Please do not apply for this position if your skills and experience are not suitable as described above.

All applications that are not suitable will be immediately rejected.

Please note that only short-listed candidates will be contacted, if you have not heard from us within 7 days of submitting your CV; please consider your application unsuccessful.