Frontend Software Engineer

Harold Peñaloza

I build fast, expressive interfaces for complex products.

Product interfaces, design systems, testing, and the engineering behind them.

Frontend Software Engineer with 5 years of React experience building B2B SaaS interfaces, complex dashboards, design-system components, and frontend testing infrastructure.

Open to remote frontend roles Granada, Meta, Colombia

02 / Production record

Frontend work that changed the system.

Five years inside a complex IoT B2B SaaS product—shipping React interfaces, migrating foundations, improving test feedback, and helping teams work with more confidence.

Ubidots S.A.S.

Frontend Developer

February 2021 — April 2026 Colombia / Remote

Built and maintained React-based frontend features across an IoT B2B SaaS platform.

Selected contributions

  1. Reduced frontend test pipeline time from roughly 2 hours to 30 minutes by leading the migration from Jest to Vitest.
  2. Led the frontend migration of the Organizations module to the internal Vulcan UI design system, delivering independently with tests and no critical production bugs.
  3. Created and maintained reusable components for Vulcan UI, helping standardize product interfaces across the platform.
  4. Reviewed code regularly to improve maintainability, prevent production issues, and align implementation with team standards.

Production toolkit

  • React
  • JavaScript
  • TypeScript
  • styled-components
  • Redux
  • React Query
  • Jest
  • Vitest
  • React Testing Library
  • Cypress
  • Webpack
  • Rspack

03 / Selected systems

Projects with a reason to exist.

A compact set of projects showing local-first product engineering, visual judgment, documentation, and practical developer workflows.

Active

Synapse Loom

Local-first notes and learning workspace that turns Markdown notes into connected knowledge and spaced-repetition review.

  • Shares a React 19 and TypeScript product surface across an installable PWA and Tauri desktop client, backed by reusable Rust domain logic.
  • Runs SQLite in WebAssembly over OPFS for durable local data and offline access, with optional sync and shared Spaces instead of a registration wall.
  • React 19
  • TypeScript
  • Rust
  • WebAssembly
  • SQLite
  • PWA

Active

harpeblue.com

Professional portfolio built as a fast, bilingual, static-first site for frontend experience, proof, and the evolving HarpeBlue identity.

  • Built with Astro to prioritize performance, SEO, maintainability, and static deployment.
  • Owns a compact local visual system and bilingual content architecture without a client-side application runtime.
  • Astro
  • TypeScript
  • CSS
  • Accessible HTML

Active

HarpeBlue Signal

Framework-agnostic visual identity system built with CSS tokens, themes, utilities, and examples.

  • Creates a reusable visual foundation for HarpeBlue projects without depending on a specific frontend framework.
  • Includes a public playground and documentation examples using pure CSS and lightweight JavaScript tooling.
  • CSS
  • Design Tokens
  • JavaScript
  • GitHub Pages

04 / Capability matrix

How I approach frontend work.

Tools matter, but the useful signal is where they appear: product UI, data flows, testing, tooling, and reusable systems.

  1. Product UI

    Responsive interfaces and reusable product patterns.

    • React
    • JavaScript
    • TypeScript
    • HTML
    • CSS
    • styled-components

  2. State and Data

    Predictable client state and asynchronous product data.

    • Redux
    • Context API
    • React Query
    • Formik

  3. Testing

    Fast feedback from components to complete browser flows.

    • Jest
    • Vitest
    • React Testing Library
    • Cypress

  4. Tooling

    Build systems and everyday engineering foundations.

    • Webpack
    • Rspack
    • Git
    • GitHub
    • npm

  5. UI Systems

    Consistency across complex, evolving interfaces.

    • Design systems
    • Responsive UI
    • Dashboards
    • Reusable components

  6. Workflow

    Making changes understandable, reviewable, and safer.

    • Code review
    • Frontend migrations
    • Linux
    • AI-assisted development

Open channel

Bring me the interface that needs clarity.

I'm open to remote Frontend Software Engineer roles centered on React, product UI, design systems, testing, and thoughtful AI-assisted workflows.

Availability
Open to remote frontend roles
Based in
Granada, Meta, Colombia
Professional profiles
harpeblue.com