Dio Castillo

Co-owner and lead technical consultant providing end-to-end application support and infrastructure management for small business clients.

• Infrastructure Operations: Configure and maintain web environments, managing DNS propagation, SSL provisioning, email routing (MX records), and migrations across hosting platforms.
• Technical Troubleshooting: Diagnose performance, security, and connectivity issues by reviewing server logs, isolating root causes, and validating fixes to minimize downtime.
• Code-Level Support: Debug and modify HTML/CSS/JavaScript code to resolve UI rendering defects and restore functionality during critical site issues.
• Process Improvement: Author technical documentation, knowledge base articles, and standard operating procedures (SOPs) to enable client self-service and reduce recurring support tickets.
• Cloud R&D (Current Focus): Actively modernizing support protocols by deploying serverless cloud architectures on Azure and Google Cloud Platform (GCP) to validate infrastructure-as-code and automated monitoring workflows.

Leveraged background as a Core .NET Developer to serve as the Tier 3 escalation point for critical defects in casino financial kiosks and web dashboards.

• Developer-Led Troubleshooting: Utilized access to source code to debug production incidents that Tier 1/2 could not resolve, identifying logic errors in C# and SQL that required code-level fixes.
• Incident Resolution: Reduced MTTR (Mean Time To Resolution) for high-priority outages by directly debugging integrations with external Financial Transaction APIs and CMS endpoints.
• DevOps & Release Management: Managed full-lifecycle deployments in a shared DevOps environment, utilizing Azure DevOps to build, test, and release code to production independently.
• Integration Leadership: Led the technical integration for key Casino Management System (CMS) projects, ensuring seamless data exchange and high availability.
• Operational Excellence: Conducted Root Cause Analysis (RCA) on recurring defects and refactored logging standards to improve system observability.

Maintained and supported mission-critical GIS (Geographic Information Systems) applications used by law enforcement agencies and the public.

• Public Safety Systems: Supported the CrimeView and CrimeMapping platforms, ensuring high availability for dual use-cases: real-time situational awareness for police units and transparency dashboards for civilian crime tracking.
• Legacy Application Support: Managed the lifecycle and stability of Silverlight (Web) and WPF (Desktop) clients, troubleshooting UI rendering and data binding issues.
• Geospatial Data Integrity: Debugged integration issues within ESRI ArcGIS-based workflows, ensuring accurate plotting of crime statistics and real-time police vehicle location tracking.

• Legacy System Support: Extended the lifecycle of enterprise legacy applications (Accounting & Operations) by resolving code defects and optimizing SQL database performance.
• Technical Escalation: Led root cause analysis (RCA) for production data anomalies, reviewing application logs and SQL workflows to restore service for internal business units.
• Process Automation: Developed scripts to automate manual data reporting tasks, significantly reducing operational overhead for the billing department.

• Defect Resolution: Investigated software defects by analyzing system logs, reproducing issues in test environments, and documenting detailed root cause analysis (RCA).
• Release Validation: Executed rigorous functional and regression testing for system updates, validating expected behavior before deployment to training environments.
• System Debugging: Bridged the gap between support and engineering, assisting senior developers with debugging complex logic errors.
• SDLC Compliance: Maintained technical documentation, test plans, and issue tracking records to support a structured, compliance-driven workflow.

• Tier 2 Technical Support: Provided comprehensive desktop, network, and application support for internal users, resolving hardware failures and OS configuration issues.
• Incident Management: Diagnosed system failures and maintained accurate incident records, ensuring timely resolution to minimize downtime.
• System Administration: Managed user provisioning, workstation imaging, and basic network troubleshooting in a secure defense environment.

Managed logistics, inventory control, and requisitioning for aviation maintenance operations.

• Logistics Systems: Utilized the NALCOMIS database to track mission-critical aviation assets and process requisitions.
• Operational Readiness: Managed high-volume inventory control operations aboard the USS Kitty Hawk, ensuring 100% accountability.
• High-Pressure Adaptability: Demonstrated reliability, rigorous attention to detail, and adaptability while working in dynamic, mission-driven military environments.
• Transition Excellence: Aggressively upskilled during active service, earning an A.S. Degree and multiple technical certifications (MCSE, A+, Net+) to launch a successful civilian IT career immediately upon discharge.

• Google Cloud: Cloud Digital Leader
• Google Cloud: Generative AI Leader
• Microsoft Azure: Azure Fundamentals (AZ-900)
• Microsoft Azure: Azure AI Fundamentals (AI-900)
• Nucamp Bootcamp: Full Stack Web & Mobile Development (MERN Stack) - 2022
• Google Career Certificate: IT Support Professional (In Progress - Refreshing Infrastructure & IT Security Skills)

• Microsoft: Certified Systems Engineer (MCSE) - Windows NT 4.0 (Good-For-Life)
• CompTIA: A+ Certified Technician - Hardware & OS (Good-For-Life)
• CompTIA: Network+ Certified Professional (Good-For-Life)
• Engineering License: Engineer in Training (EIT) - Board of Professional Engineers and Land Surveyors