John Ryan Villar

Full-Stack Developer with 3+ years of experience developing, enhancing, and supporting enterprise ERP applications using C#, ASP.NET Core, ASP.NET Framework, Microsoft SQL Server, Liquibase, and Sencha Ext JS. Experienced in developing and implementing RESTful APIs, creating full-stack features, optimizing database performance, and contributing to the modernization of legacy ASP.NET Framework applications to ASP.NET Core. Strong background in analyzing, debugging, and resolving complex production issues while delivering scalable, reliable, and maintainable solutions across inventory and business-critical workflows.

Junior Application Developer at iRely Philippines, Inc. (2023-03 – 2026-08)

• Maintained and enhanced the i21 ERP system, contributing to the modernization from legacy ASP.NET Framework 4.5 to ASP.NET Core, improving performance, scalability, and maintainability.
• Built and enhanced full-stack features using C#, ASP.NET Core Web API, ASP.NET Framework, Microsoft SQL Server, and Sencha Ext JS for Inventory Control workflows.
• Designed and implemented REST APIs, business logic, and frontend components for inventory processes including receipts, shipments, transfers, inventory count, adjustments, and stock management.
• Developed and optimized SQL Server objects including stored procedures, views, functions, and queries to support core ERP operations.
• Managed database changes using Liquibase, implementing version-controlled schema updates and deployments across environments.
• Supported integration across multiple ERP modules, including Inventory, Accounts Receivable, Accounts Payable, and General Ledger, ensuring seamless data flow and consistency across business processes.
• Diagnosed and resolved production issues involving application errors, data inconsistencies, and business logic defects.
• Improved system performance through query optimization, indexing strategies, and stored procedure tuning.
• Contributed to ERP migration efforts, bug fixes, and version upgrades to maintain system stability and reliability.

Bachelor of Science in Information Technology – STI College Ortigas (2022)