TA and Platform Engineer (RHEL & OCP Specialist)

ARISTON SERVICES PTE. LTD.; Singapore; On-site; SGD 100,000 - 140,000; Full time

Job summary

ARISTON SERVICES PTE. LTD. is seeking a senior RHEL/OCP platform administrator in Singapore to own and operate enterprise Linux and OpenShift environments. You will manage OS patching, hardening, and subscription lifecycle while running OCP clusters, machine-config-driven node customization, and secure container workflows.

You will collaborate with build teams on integration points, support multi-environment deployments, and contribute to DevSecOps practices with CI/CD and IaC processes.

Qualifications

• Hands-on experience administering RHEL 8/9 in enterprise production environments.
• Proficiency in OS patching, package management (dnf/yum), SELinux enforcement, and CIS/DISA benchmarks.
• Experience with RHEL EUS lifecycle management and version upgrades.
• Familiarity with RHEL subscription management, satellite server, and image-based deployments.

Responsibilities

• Own and maintain the RHEL OS fleet underpinning OCP worker/control-plane nodes and non-containerised application servers.
• Plan and execute RHEL OS patching cycles with minimal service disruption.
• Implement and validate OS hardening benchmarks — SELinux policies, firewalld rules, auditd configuration, and cryptographic policy settings.
• Troubleshoot system-level issues and manage subscriptions, entitlements, and image registries.
• Deploy, upgrade, and maintain OCP 4.x clusters including control plane and etcd health.
• Configure MCO for node OS customization and perform certificate rotation.
• Manage OCP networking, ingress, and HAProxy tuning for enterprise workloads.
• Administer Quay mirror registry and coordinate vulnerability remediation.
• Apply RBAC, SCCs, policies, and quotas across namespaces; support JVM/container tuning.

Skills

RHEL Administration

OS Patching

SELinux & CIS Hardening

OCP Administration

RBAC & Networking (OCP)

Tools

Quay Registry

RHEL Satellite

Job description

Main Role and Responsibilities

RHEL Platform Management (Primary Focus)

• Own and maintain the RHEL OS fleet underpinning OCP worker/control-plane nodes and non-containerised application servers
• Plan and execute RHEL OS patching cycles (EUS channel management, kernel upgrades, reboot sequencing) with minimal service disruption
• Implement and validate OS hardening benchmarks — SELinux policies, firewalld rules, auditd configuration, and cryptographic policy settings
• Troubleshoot system-level issues: kernel parameters, resource limits (ulimits, cgroups), storage mounts (NFS, iSCSI, SMB/CIFS PVs on OCP)
• Manage RHEL subscriptions, entitlements, and satellite/image registries

OCP Cluster Administration (Primary Focus)

• Deploy, upgrade, and maintain OCP 4.x clusters — including control plane, etcd health, and worker node lifecycle
• Configure and manage OCP Machine Config Operator (MCO) for node-level OS customisation: chrony NTP, SSH hardening, kernel arguments, and custom MachineConfigs
• Manage cluster certificates, ingress/route configurations, HAProxy timeout tuning for long-running enterprise workloads (e.g., Pega BIX, batch jobs)
• Administer Quay mirror registry — image mirroring, vulnerability scanning results, VAPT remediation for bundled components (e.g., jQuery CVEs)
• Implement OCP RBAC, SCCs, network policies, and resource quotas across multiple namespaces and project environments
• Support JVM and container resource tuning for Java workloads on OCP (heap sizing, Metaspace limits, G1GC flags, container memory budgeting)

Application Platform & Integration Support

• Take ownership of one or more application platforms (e.g., Pega Infinity, WebSphere, IBM MQ) — covering setup in HA mode, application patching, and ongoing operational support
• Participate in architecture sessions with build teams, advising on integration points (web services, MQ, SFTP, API gateway)
• Support container provisioning, image lifecycle, and deployment of containerised services across DEV / SIT / UAT / PROD environments

Operational Governance & Security

• Define and execute operational processes: OS patching, application-level patching, performance monitoring, housekeeping, backup and recovery
• Support VAPT engagements — assess Nessus/vulnerability findings, coordinate remediation, and produce risk acceptance or remediation reports
• Apply government-grade security hardening principles (IM8 compliance, SSCT framework, CIS benchmarks) across RHEL and OCP layers
• Contribute to DevSecOps tooling and automation concepts — CI/CD pipelines, IaC, and operational runbooks
• Support AWS administration tasks where applicable (CloudWatch monitoring, IAM, S3, hybrid integration)

Top 3 Must-Have Skills

RHEL System Administration (Required — Primary Differentiator)

• Hands-on experience administering RHEL 8/9 in enterprise production environments
• Proficiency in OS-level patching, package management (dnf/yum), SELinux enforcement, and system hardening per CIS/DISA benchmarks
• Experience with RHEL Extended Update Support (EUS) lifecycle management and version upgrades
• Familiarity with RHEL subscription management, satellite server, and image-based deployments (RHEL Image Mode / Bootc)

OpenShift Container Platform (OCP) Administration (Required — Primary Differentiator)

• Hands-on experience deploying, configuring, and administering OCP 4.x clusters (bare metal or IaaS)
• Proficiency with OCP Day-2 operations: node management, Machine Config Operator (MCO), cluster upgrades, certificate rotation, and resource quota management
• Experience with OCP networking (Routes, Ingress, HAProxy), storage (PV/PVC, storage classes), and role-based access control (RBAC)
• Familiar with OCP security hardening: SSH cipher/MAC remediation via MCO, SCC policies, network policies, and image vulnerability scanning (Quay/Clair)
• Experience with Quay registry administration including mirror registry setup for air-gapped or restricted environments

Enterprise Container Architecture & Integration Platforms

• Designing and operating multi-tier containerised architectures on OCP/Kubernetes
• Working knowledge of IBM MQ messaging — queue manager setup, channel administration, troubleshooting, and HA configuration
• Familiar with microservices architecture, API gateway integration, and container image lifecycle management

Minimum 3 years TA / infra / cloud working experience