Senior Systems Administrator | Application Support Engineer | Linux | Automation
MJ
Looking for a job
Melissa Umanzor Jiménez
@melissaumanzorjimnez
Senior Systems Administrator with 12+ years of experience supporting enterprise RHEL and hybrid cloud environments
Costa RicaWhat I'm looking for
At NTT Data / Citibank, I resolved complex application and infrastructure issues in RHEL production environments through log analysis, root-cause analysis, and safe remediations.
I planned Linux patch management and capacity planning, and used Chef, Ansible, Bash, and Python to streamline operational tasks. I also developed custom Ansible playbooks to support deployment workflows.
At Dell Technologies, I monitored and maintained Dell Linux infrastructure across AWS EC2, VMware Cloud on AWS, and on-premises servers, using CloudWatch and Nagios to track system health.
At IBM, I provided SAP Basis administration for critical application infrastructure and led knowledge migrations, authored SOPs, and mentored team members. I’ve also explored AI-assisted automation through personal projects using Google Antigravity IDE and Claude Code.
Experience
Work history, roles, and key accomplishments
NC
Unix L3 Senior Systems Administrator
NTT Data / Citibank
Jun 2021 - Apr 2026 (4 years 10 months)
Resolved complex application and infrastructure issues in RHEL production environments, executed Linux patch management, and leveraged Chef and Ansible for configuration management. Provided on-call support and administered high-availability clusters using Veritas Cluster Server.
DT
Monitored and maintained Dell Linux infrastructure across approximately 450 servers on AWS EC2, VMware Cloud on AWS, and on-premises physical infrastructure. Supported Linux workloads on VMware vSphere ESXi hypervisors.
Supported large-scale Unix infrastructure for CIBC in a regulated banking environment. Administered user ID lifecycle via LDAP, eTrust, and Active Directory, ensuring least-privilege access and compliance.
Provided SAP Basis administration and supported critical application infrastructure, maintaining high availability and performance across SAP applications, web servers, and SQL databases. Led knowledge migrations and authored technical documentation.
Education
Degrees, certifications, and relevant coursework
Tecnológico de Costa Rica
Python Express AI-Driven, Python
Completed Python Express AI-Driven training.
AXELOS
ITIL – IT Service Management, IT Service Management
Completed ITIL – IT Service Management certification.
Amazon Web Services (AWS)
AWS Cloud Practitioner Essentials, Cloud Computing
Completed AWS Cloud Practitioner Essentials certification.
IBM
SAP Basis Administration, SAP Basis Administration
Completed SAP Basis Administration training.
Oracle University
Oracle Cloud Infrastructure, Cloud Infrastructure
Completed Oracle Cloud Infrastructure training.
IC
ICC
Microsoft SQL Server, Microsoft SQL Server
Completed Microsoft SQL Server training.
IC
Instituto Centroamericano de Computación
Técnico en Servidores Linux, Linux Servers
Completed Técnico en Servidores Linux program.
IC
Instituto Centroamericano de Computación
Administrador del Sistema Linux, Linux System Administration
Completed Administrador del Sistema Linux program.
Availability
Looking for a job
Location
Costa RicaAuthorized to work in
Salary expectations
60k-70k USD
Social media
Job categories
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