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Ivan Diaz ⁄ Senior React DeveloperAvailable for contract

Senior React Developer — 東京発信 / signal

IvanDiaz

React · Next.js · TypeScript

I build and ship production web apps — fast, and the way you'd build them yourself.

Hire me on UpworkSee the work →
5+ yrs
React & TypeScript in production
−30%
faster after a legacy frontend rebuild
6K+
users on the platform I ship
Ivan Diaz · GDL
01 — 仕事 / what I do

Built to ship

Frontend architecture that scales, features shipped end to end, and the APIs behind them.

P.01

Frontend Architecture

React / Next.js apps built to scale — state management, performance and a component library your team can keep building on.

P.02

Feature Development

Ship new features into your existing React or Next.js app, from design through deployment, without breaking what already works.

P.03

Performance & Modernization

Refactor a slow or dated frontend into something fast and maintainable — past rebuilds cut load times by 15–30%.

P.04

APIs & Integration

Need the backend too? Clean, documented REST APIs on Node.js or .NET, wired to the frontend end to end.

02 — 技術 / the stack

Top to bottom

One person across every layer — no handoffs between frontend and backend.

Frontend
  • React
  • Next.js
  • TypeScript
  • Redux
  • Zustand
  • Jest
Backend
  • .NET
  • Node.js
  • Express
  • REST APIs
Data
  • SQL Server
  • MongoDB
Cloud & Tooling
  • Azure
  • AWS (S3, IAM)
  • Git
  • Jira
03 — 経歴 / track record

Where I've shipped

  1. Nexaminds

    Oct 2024 — Present

    Fullstack Developer L3

    Build and ship React/Next.js features for an enterprise vendor-carrier logistics platform serving ~6,000 users. Led a full frontend modernization that cut load times 30%, designed the global state layer with Zustand, and drive code quality through reviews and testing.

  2. Brightcove

    Sep 2022 — Aug 2024

    Software Engineer

    Built and maintained the React / TypeScript / Redux web client of a multi-platform streaming CMS. Shipped features, fixed critical bugs, and refactored legacy code to cut load times 15%.

  3. Tech Mahindra

    Sep 2021 — Sep 2022

    Software Developer

    Front-end consultant building a React / Redux / TypeScript SPA with production support, responsive design, and a reusable component library that cut duplication.

  4. Infobip

    Feb 2021 — Sep 2021

    Fullstack Developer

    Designed a new UI for a billing system that improved the finance team's efficiency, and built a RESTful API for secure data transfer.

Education — B.S. Computer Engineering — UNIVA, Guadalajara
04 — 作品 / selected work

The work

Case studies in progress. Client work is under NDA — these are builds I can show end to end.

In progress

Analytics Dashboard

React + .NET admin panel with role-based access, CRUD and live metrics. Full case study coming soon.

  • React
  • Next.js
  • .NET
  • SQL Server
Planned

Booking System

Appointment scheduling app with calendar, notifications and a customer portal.

  • Next.js
  • Node.js
  • MongoDB
Available

Your project here

Have something in mind? This slot is open — let's talk about what you need built.

  • React
  • .NET
  • Azure
05 — 連絡 / get in touch

Let's build

Available for part-time freelance — evenings & weekends. Send a short note about what you need built and I'll get back to you.

ivan@lowtus.meUpworkLinkedInGitHub