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Juan Villa

From idea to production.

I'm Juan Carlos Villa Rivera, a full-stack developer and solutions architect. I design the architecture, build the apps with their APIs, then set up the Azure and Microsoft 365 services behind them.

Open to full-stack and architecture roles, as well as consulting

About

I turn ideas into working products, then keep them running. For Cotton Holdings, CAZ Investments, PrimeFire, and Carrier, I have shaped features with the business, designed the architecture, and built the apps. I also set up the Azure and Microsoft 365 pieces that hold them together. AI tools are part of how I work every day, so the team moves faster without cutting corners.

Right now

  • Cotton Holdings Inc.

    Full-stack developer

    Disaster recovery and infrastructure support

  • CAZ Investments

    Full-stack software engineer

    Alternative investment firm

  • Carrier

    Full-stack consultant (external)

    Climate and energy technology: HVAC, refrigeration, and controls

  • Developer's Romo

    Web application developer

    Software, cloud, and Microsoft 365 solutions studio

Bigger projects

For bigger projects I bring in a network of developers I trust, so you keep one point of contact and still get a team that covers the whole stack.

Selected work

The platforms, integrations, and websites I have built, most important first.

Cotton HoldingsSep 2022 – Present

Cotton Cloud

Cotton Holdings runs disaster recovery and infrastructure support. I build across its internal platform, from the sales pipeline on the IFS ERP to forms, approvals, and reliability.

  • Leads, opportunities, deals, and projects managed through the IFS ERP.
  • Form.io forms and native job requisitions, with scheduled auto-approval or bulk approval.
  • Addresses validated with Smarty, case studies with PDFs, custom pages, and a price list catalog.
  • Sentry error tracking, cache recovery, role permissions, plus tests across the API and the app.
  • React
  • TanStack
  • FastAPI
  • PostgreSQL
  • IFS ERP
  • Form.io
  • Sentry

CAZ InvestmentsApr 2026 – Present

Investor platform

CAZ Investments gives investors access to private markets. I build its web products, connecting the investor experience, CMS workflows, and enterprise systems.

  • Sign-in on Auth0 with multi-factor authentication, and access control tied to Salesforce.
  • Documents delivered as watermarked PDFs through signed URLs from Azure Blob Storage.
  • A content migration to Strapi, with extraction, transformation, and publishing automated.
  • Onboarding, dashboards, forms, notifications, and Media & Insights.
  • React
  • TypeScript
  • Auth0
  • Salesforce
  • Strapi
  • Azure Blob Storage

PrimeFireSince 2025

Multi-tenant platform

I built most of PrimeFire's internal platform (the FastAPI back end and the Angular app), used by its staff as well as its external clients.

  • A database per tenant: each external client's data lives in its own SQL Server database.
  • External sign-ups approved by an admin and assigned a tenant. Staff sign in with Azure AD.
  • Roles with view and edit permissions per module, plus email branding per tenant.
  • Employees synced from Microsoft 365, plus quotations, agreements, IT tickets, timesheets, time off, and expenses, with Teams notifications and Excel exports.
  • FastAPI
  • Python
  • SQL Server
  • Angular
  • Azure AD
  • Microsoft Graph

PrimeFireJun 2025 – Sep 2025

Market websites

PrimeFire designs, installs, and maintains fire protection systems. I designed and built its two websites: one for Puerto Rico, one for the Dominican Republic.

  • English and Spanish on every page, switched in place.
  • Careers and FAQs on both sites, plus a page for each fire protection service on primefire.us.
  • Contact forms delivered through my contact service on Azure and Microsoft 365.
  • HTML
  • CSS
  • JavaScript
  • FastAPI
  • Microsoft Graph

primefire.usprimefire.do

primefire.do
Home page of primefire.do, the PrimeFire website for the Dominican Republic
primefire.us
Home page of primefire.us, the PrimeFire website for Puerto Rico

CarrierAug 2026 – Present

IT inventory workspace

Carrier builds climate and energy technology. As an external consultant I am building its internal IT inventory, both the React app and the ASP.NET Core API.

  • Licenses, device inventory, applications, and servers, with full CRUD flows. License keys stay masked until someone reveals them.
  • An inventory dashboard, an admin area, and form options driven by catalogs.
  • In the API: licenses, catalog entries, applications linked to users many-to-many, plus EF Core migrations on SQL Server and xUnit tests.
  • ASP.NET Core
  • C#
  • Entity Framework Core
  • SQL Server
  • React
  • TanStack

fivePin

Rubric estimating

fivePin builds software for construction and other industries. Rubric is its estimating app for construction bids. I built features across its React app and its .NET API.

  • Excel import and export of bid lines: a downloadable template, validation that points to the exact cell, plus a quick import for electrical lines.
  • Mineral wool calculations, material totals and ordering, penetration sizes in fractions, plus a reset for bid lines.
  • In the .NET API: bid lines, materials summaries, endpoints to reset or delete lines, plus integration tests and EF Core migrations.
  • React
  • TypeScript
  • Chakra UI
  • TanStack Query
  • .NET
  • Entity Framework Core

More work

Developer's Romo

Contact form service

One FastAPI service on Azure that receives the contact forms of several client sites and delivers each message through Microsoft 365.

  • Per-site branding, dynamic fields, and validated attachments.
  • Mail profiles that send as the right Microsoft 365 mailbox for each client.
  • FastAPI
  • Azure App Service
  • Microsoft Graph
  • Exchange Online

Live sites

Client sites and exactly what I did on each. Each site opens in a new tab.

SupportUI changes, support, and contact form improvements. The forms deliver through Azure and Microsoft 365.

Experience

9 roles since 2021, several of them running in parallel. Open a role for the details.

  1. Disaster recovery and infrastructure supportFull-timeHybrid

    Full-stack developer across Cotton Cloud, the company's internal platform: the sales pipeline on the IFS ERP, forms with their approvals, customer records, and the tooling that keeps it reliable.

    • The sales pipeline on the IFS ERP: business leads, opportunities, deals, and projects managed through the IFS API, with restoration leads linked to construction leads.
    • Form.io forms and native job requisitions: approvals by group or person, scheduled auto-approval, bulk approval or disapproval with history, plus notifications with PDFs.
    • Customers with addresses validated by Smarty, ZIP code resolution, master addresses, and bulk uploads.
    • Case studies with photo Q&A, ratings, and PDFs; custom pages built from widgets; a price list catalog; IFS document previews and zip downloads.
    • Sentry error tracking with filtering, cache recovery for Delta Lake and IFS data, role permissions, a form drafts API for the mobile app, plus tests across the API and the app.
    • React
    • TypeScript
    • TanStack
    • FastAPI
    • Python
    • PostgreSQL
    • IFS ERP
    • Form.io
    • Sentry

  2. Alternative investment firmPart-timeRemote

    Web products for an investment platform, integrating user experiences, CMS workflows, and enterprise systems.

    • Secure sign-in flows with Auth0 and Salesforce, plus access controls on protected content.
    • Secure document delivery with PDF watermarking, signed URLs, and Azure Blob Storage.
    • Led the content migration to Strapi: content normalized, with extraction, transformation, and publishing automated.
    • Frontend, backend, and CMS architecture for onboarding, dashboards, forms, notifications, plus Media & Insights.
    • React
    • TypeScript
    • Auth0
    • Salesforce
    • Strapi
    • Azure Blob Storage

  3. Fire protection systems: design, installation, and maintenanceFreelanceRemote

    Designed and built primefire.do, the official website for the Dominican Republic market.

    • The brand's identity adapted to the local market, with a modern, responsive design.
    • Web development
    • Web design

  4. Fire protection systems: design, installation, and maintenanceFreelanceRemote

    Designed and built primefire.us, the official website for Puerto Rico.

    • A professional, responsive site that puts the company's services first.
    • Web development
    • Web design

  5. Fire protection systems: design, installation, and maintenanceFreelanceRemote

    Moved the company's email from cPanel to Microsoft 365 and ran it afterwards.

    • Mailbox management and email signatures in Exchange Online.
    • Technical support for the teams adopting the new tools.
    • Microsoft 365
    • Exchange Online
    • cPanel

  6. Climate and energy technology: HVAC, refrigeration, and controlsContractRemote

    External consultant through Developer's Romo, building Carrier's internal IT inventory: the React app and the ASP.NET Core API.

    • Licenses, device inventory, applications, and servers in the app, with full CRUD flows. License keys stay masked until someone reveals them.
    • The inventory dashboard, the admin area, catalog-driven form options, plus the app's routing and layout.
    • Data model work in Entity Framework Core: application-user relationships, catalog entries, licenses, all with migrations and xUnit tests.
    • ASP.NET Core
    • C#
    • Entity Framework Core
    • SQL Server
    • React
    • TypeScript
    • TanStack

  7. Software, cloud, and Microsoft 365 solutions studioFreelanceRemote

    Platforms, integrations, and websites for the studio's clients.

    • Built most of PrimeFire's internal platform, both the FastAPI back end and the Angular app.
    • A shared contact-form service on FastAPI and Azure that delivers messages from client sites through Microsoft 365.
    • Contact forms, updates, and maintenance for client websites. SSL certificates and servers managed in Plesk or cPanel.
    • FastAPI
    • Python
    • Angular
    • SQL Server
    • Azure App Service
    • Microsoft Graph
    • PHP

  8. Software development and consulting

    Built features for Rubric, fivePin's estimating app for construction bids, in its React app and .NET API.

    • Excel import and export of bid lines in the React app, with validation that points to the exact cell.
    • Mineral wool calculations, material totals, and a reset for bid lines.
    • Electrical estimating features in the .NET API: bid lines, materials summaries, endpoints to reset or delete lines, plus integration tests.
    • React
    • TypeScript
    • C#
    • .NET
    • Entity Framework Core
  9. COVEICyDETWeb developerDec 2021 – Jun 20227 mos

Capabilities

Development is the core, but I also shape the idea, design the architecture, then run the cloud and Microsoft 365 setup it lives on.

  • Architecture and product

    From a rough idea to a plan the team can build: scope, systems, and trade-offs.

    • Solution architecture
    • Product ideation
    • API design
    • Data modeling
    • Technical consulting

  • Front end and UI

    Interfaces that feel fast and clear, designed by the same person who builds them.

    • React
    • Next.js
    • TypeScript
    • Angular
    • TanStack
    • Tailwind CSS
    • UI and UX design

  • Back end

    APIs and services that stay readable as they grow.

    • FastAPI
    • Python
    • ASP.NET Core
    • C#
    • Entity Framework Core
    • PHP
    • Strapi

  • Data

    Schemas, migrations, caching, and the databases behind them.

    • PostgreSQL
    • SQL Server
    • Redis
    • Database administration
    • PyMuPDF

  • Azure and Microsoft 365

    The cloud and tenant work that most developers leave to someone else.

    • App Service
    • Tenants and app registrations
    • Azure Blob Storage
    • Microsoft Graph
    • Microsoft 365 administration
    • Exchange Online
    • Teams

  • Identity and security

    Sign-in, access, and documents that only reach the right people.

    • Auth0
    • Azure AD
    • MSAL
    • Salesforce
    • JWT
    • Signed URLs
    • PDF watermarking
    • SSL certificates

  • AI and automation

    AI tools in the daily workflow, self-hosted agents set up end to end, plus chatbots and automations that save real hours.

    • OpenAI Codex
    • Anthropic Claude
    • GitHub Copilot
    • Cursor
    • Hermes Agent
    • OpenClaw
    • Chatbots
    • Workflow automation

  • Quality and delivery

    Tests and pipelines so changes ship without surprises.

    • Vitest
    • Playwright
    • Pytest
    • xUnit
    • GitHub Actions
    • Sentry

Education and certification

  • Engineering degree in Systems Engineering

    Instituto Tecnológico Superior de Xalapa

    Aug 2018 – Aug 2023

  • Business English Basic 1

    Top Quality Training Business

    Issued Nov 2023, credential BME-130201-738-0013

Have a role or a project in mind?

For bigger projects I bring in a network of developers I trust, so you keep one point of contact and still get a team that covers the whole stack.

  • Full-stack development
  • Solution architecture
  • Azure and Microsoft 365
  • UI and UX design
  • AI automation and bots
Email me[email protected]
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