Description du poste
Ensure the availability, performance, and security of Linux Server environments and related services for multiple clients by delivering operations, automation, and Level 2/3 support with on call duty.
CONTEXT
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Shared services team of 5 administrators supporting multiple client environments (multi-tenant).
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Responsible for operational availability, performance, and security of Linux infrastructure across on-prem and cloud.
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Rotating on-call to ensure service continuity per contractual SLAs.
Main Responsibilities:
System administration:
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Install, configure, and maintain Linux servers (e.g. Ubuntu, Debian, CentOS, RHEL).
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Perform regular patching, upgrades, and system hardening.
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Manage users, groups, permissions, and sudo/access policies.
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Ensure system stability, performance, and capacity planning.
Shared services and platforms:
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Administer shared services (e.g. DNS, NTP, SMTP relays, web servers, file servers).
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Support application teams using the shared Linux infrastructure.
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Maintain and optimize virtualization and/or container platforms (VMware, KVM, Docker, Kubernetes – depending on the environment).
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Contribute to standardizing environments and configurations across multiple teams.
Monitoring, incident management, and on-call:
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Configure and maintain monitoring and alerting tools (e.g. Zabbix, Prometheus, Nagios, Grafana).
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Investigate and resolve incidents affecting shared systems and services.
Participate in a rotating on-call duty schedule (24/7 support):
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Respond to alerts within defined SLAs.
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Perform first analysis, mitigation, and escalation when needed.
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Communicate clearly with stakeholders during major incidents.
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Contribute to post-incident reviews (RCA) and continuous improvement actions.
Security and compliance:
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Apply security best practices and hardening guidelines on Linux systems.
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Work with security teams to identify, prioritize, and remediate vulnerabilities.
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Manage firewalls, VPN access, and secure remote access (SSH, bastion/jump hosts).
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Ensure compliance with internal policies and external regulations where applicable.
Backup, recovery, and continuity:
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Regularly test recovery and disaster scenarios.
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Help define and meet RPO/RTO targets for critical services.
Automation and industrialization:
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Use scripting (Bash, Python, etc.) to automate recurring operational tasks.
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Use configuration management tools (e.g. Ansible, Puppet, Chef, SaltStack) to maintain consistent environments.
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Contribute to infrastructure as code and standard operating procedures.
Documentation and collaboration:
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Create and maintain clear technical documentation, runbooks, and on-call procedures.
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Collaborate closely with application, network, security, and other support teams.
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Share knowledge within the team and help onboard new colleagues.
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Participate actively in team meetings, capacity reviews, and planning sessions.
