+ Successfully converted physical server infrastructure into a scalable and fault-tolerant redundant virtual infrastructure using Proxmox VE hypervisor. System has easily scaled up from 5 VMs to over 20 VMs in just one year. Deployed multiple Proxmox Backup server to auto backup all VMs.+ Consolidated over 70 individual workstations into a thin-client model by migrating windows user profiles into high capacity servers. Deployed Apache Guacamole (clientless RDP) gateway for thin-client connection to the servers. + Implemented a multi-site network infrastructure and split core servers between the two sites. Deployed pfSense firewall to establish site-to-site VPN and for security protection.+ Converted a cloud-hosted DNS and email server to on-premise servers, along with Proxmox Mail Gateway to enhance email security.+ Implemented a comprehensive data backup solution with redundant on-site and off-site copies to recover data during disaster recovery situations and to easily restore data for business continuity. + Maintain and operate all network equipments, including workstations, servers, switches, routers, firewalls, Internet, and VoIP phone system. Patch all security updates.+ Configure user workstation with needed applications and system access for new hires.+ Provide IT help desk support to over 70 internal employees and national outside sales team.+ Manage procurement of IT equipments, including hardware, software, and phone system.+ Generate various ad-hoc reports and assist in application development as needed.

Local CLEC (Competitive Local Exchange Company) focused on providing affordable cellular, local, long distance, and international calling services to residential and small business.+ Managed back office operations, including customer service, line provisioning, tech dispatching, billing, and customer service. + Maintain and operate IT infrastructures, including workstations, servers, switches, routers, firewalls, and phone system.+ Performed a cost analysis study of underlying carriers to ensure the least cost line provisioning, audit and reconcile billing discrepancies with ILEC (AT&T). Increased customer base up to 5,000 by launching a government subsidized prepaid Landline and wireless phone service and through developing reseller/agent channel program.+ Developed secured web application to sell pin-less cellular airtime cards for resellers.+ Successfully launched the 4G WiMAX wireless Internet product line as one of the National Master Dealer of Clearwire. Lead project manager for new market launches in 5 states.

+ Founded a startup I.T. consulting firm specializing on providing a full range of IT services to small businesses, including computer and networking support, POS system implementation, business phone system support, and comprehensive IT consultation.+ Developed custom ERP system (PO, inventory, CRM, invoicing, and accounting modules) for an embroidery/printing manufacturing company. Also developed restaurant POS system.

Privately held local community bank with 8 branches and over 150 employees. Serving the financial needs of the Korean American community along with other ethnic groups.+ Reduced annual I.T. budget by 20% by transitioning outsourced I.T. service in-house. + Led of team of 5 IT specialists in daily IT operations, including maintenance of workstations, servers, printers, and backup tapes. IT help desk to over 150 employees, and Internet Banking system support.+ Assisted COO in migrating core banking application system. Assisted vendor’s lead Project Manager in coordinating & managing system testing and employee training.