Open to opportunities

John De Leon

@johndeleon1

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Full-Stack Software Developer focused on secure, end-to-end enterprise systems using modern Rust and .NET.

Mexico

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What I'm looking for

I’m looking for a role where I can build secure, end-to-end systems, translate business requirements into reliable software, and modernize legacy apps—using smart AI assistance plus rigorous code review and continuous learning.

I’m a self-taught Full-Stack Software Developer with 2+ years of professional experience building end-to-end enterprise systems, plus earlier experience as an IT Lead developing in-house solutions. I translate business requirements into functional software under secure architecture principles, coordinating with end users while keeping quality high through continuous learning and hands-on iteration.

At Air Treatment Corporation, I maintained and evolved an enterprise desktop CPQ application for 250 sales users and modernized authentication from basic auth to OIDC using Azure Entra ID and Azure Secrets management. I also hardened SQL Server access with Entra-only authentication and Entra ID–linked groups, refactored synchronous flows to asynchronous operations, and resolved a critical monetary precision bug; on the side, I designed and implemented an end-to-end CPQ prototype in Rust (Axum + Dioxus) with PostgreSQL and security-minded architecture.

Experience

Work history, roles, and key accomplishments

Full-Stack Software Developer

Air Treatment Corporation (UMAS)

Feb 2024 - Apr 2026 (2 years 2 months)

Maintained and evolved a .NET/WPF enterprise desktop CPQ application serving 250 sales users, enhancing quote, project, and Word/PDF/Excel reporting. Migrated authentication to OAuth2/OIDC with Azure Entra ID and implemented Azure Key Vault secrets management while hardening SQL Server access via Entra-only authentication.

C++.NET Framework WPF SQL Server Azure Entra OAUTH2 Azure Key Vault Entity Framework Security Hardening

Technology Support Engineer

Seguritech Privada

Aug 2023 - Nov 2023 (3 months)

Installed, configured, and integrated IP cameras into a C4 surveillance system. Performed electrical setup and site surveys for intelligent monitoring points (PMIs).

IP Cameras Surveillance Systems Network Integration Troubleshooting

Facilities Engineer

Toyota (PROMI)

Apr 2023 - Jun 2023 (2 months)

Maintained electrical and embedded systems plus HVAC and refrigeration equipment. Repaired motors and performed maintenance on loading docks and electrical control components.

Refrigeration Electrical & Controls Troubleshooting

Project Engineer

Grupo Carso (KB-TEL)

Jan 2023 - Apr 2023 (3 months)

Drafted blueprints for fiber-optic poles and conducted geographic site analysis. Managed record-keeping, statistical analysis, and cost estimation to support project delivery.

Geographic Site Analysis Cost Estimation Statistical Analysis Technical Documentation Record keeping

IT Lead

Chiapas Flower & El Cauca

Jan 2016 - Jan 2022 (6 years)

Developed an in-house QR inventory system with stock control and report exports, and deployed structured cabling and datacenter upgrades. Implemented IP video surveillance (32 cameras), automated backups via CobianReflector, built ~20 workstations, and delivered ongoing end-user IT support.

Structured Cabling Backups Automation