Sergio Andrés Zabala Marquez

Cut Tier 1 support case resolution times on a high-demand streaming platform by 50% by implementing structured technical workflows and SQL-driven diagnostics. Mitigated Stripe payment disputes through data-backed evidence and partnered with engineering to document system-level bugs.

Apply advanced hardware diagnostics, on-site repair, and component replacement for mobile and computer devices, managing end-to-end logistics and direct client relationships in an on-demand repair business.

Sustained a Customer Satisfaction (CSAT) score above 98% in a high-volume bilingual environment, resolving complex streaming, connectivity, and account authentication issues via chat and voice. Consistently met strict performance KPIs for schedule adherence, punctuality, and Average Handling Time.

Provided end-user technical support to customers of multiple major US telecommunications companies in a multi-client environment, troubleshooting hardware and connectivity issues and resolving billing discrepancies. Exceeded cross-selling and customer service resolution targets in a fast-paced, high-volume environment.

Led operations and commercial management across multiple store locations, using Microsoft 365 and data-driven reporting to optimize resource allocation and KPI tracking. Managed cross-functional teams, fostering a high-performance culture focused on technical quality, efficiency, and customer satisfaction.

Diagnosed and repaired mobile device hardware issues (screens, batteries, logic boards) in a high-volume retail repair environment, including accessory installation and device setup for customers.

Managed technical service operations, ensuring quality and efficiency in service delivery.

Managed and maintained a fleet of headless Raspberry Pi devices running Linux via CLI, powering automated ambient music and digital advertising networks for restaurant chains and retail stores. Used SSH extensively for remote troubleshooting, routine system updates, network optimization, and automated offline backup protocols.

Administered user accounts and mailboxes in Active Directory and O365/Exchange, managing between 50 and 100 active accounts, while supporting nationwide enterprise infrastructure including routers, servers, and network monitoring across Linux environments. Analyzed helpdesk incident support data to write comprehensive technical assistance manuals, driving self-service efficiency and streamlining I

Pursuing a Bachelor of Science in Systems Engineering, currently in progress as of 2025.

Completed programs in Computer Equipment Maintenance and Network Design & Installation from 2012 to 2015.