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Nelson ArandaTechnical Lead Frontend

Open to remote work

I build high-quality apps with people I like working with.

I'm a mobile and frontend lead from Paraguay. I've spent 5+ years building digital banking, mobility, and financial apps with React Native, Flutter, and React, 4+ of them at itti.

Email meSee my work

Geometry Dash is my favorite game, so I turned my career into a level.

Work

Four products I've built, newest first.

conto

2026 – now

An app for Paraguayan taxpayers to upload receipts, review tax assessments, and file tax returns. It launched on its own, passed 5,000 downloads on Google Play, and now lives inside ueno bank.

  • Flutter
  • Riverpod
  • GoRouter
  • Google ML Kit
  • VisionKit
  • Amplitude
Receipt in camera view

A small working version of the document scanning I built into conto: edge detection, capture, and perspective correction, all on the device.

  • I took it from zero to production, led its releases, and set up its folder structure on Clean Architecture.
  • I built the receipt upload flow: camera, gallery, cropping, and batches of up to 20 images. I also wrote a native Flutter plugin that puts ML Kit's document scanner on Android and VisionKit on iOS behind one Dart API.
  • We shipped receipt history with OCR, assessments, tax returns with PDF download, and Marangatú account linking, and we measure every funnel in Amplitude.
  • I work spec-first: I write the spec and the implementation plan for each feature, and AI agents use them as context to build it.

ubox

2026 – now

A courier micro-app inside ueno bank: a free US mailbox, shipment tracking, and pickup at partner locations.

  • Flutter
  • Dart
  • Clean Architecture
Order placed

A small working version of shipment tracking in ubox, the courier micro-app whose squad I lead.

  • I lead two micro-app squads inside ueno bank, ubox and conto, with three developers each.
  • I mentor the squad, review code, push TDD, and manage ubox's releases.
  • I work with backend, QA, and management so the team can ship without getting blocked.

muv

2024 – 2026

A Paraguayan ride-hailing and delivery platform with 450,000+ passengers and 10,000+ drivers. I worked on the driver and passenger apps, the web, and the SDK monorepo.

  • React Native
  • Expo
  • TypeScript
  • TanStack Query
  • Next.js
Ready to request a ride

A small working version of the passenger ride flow I built on Mapbox for muv: request, driver match, and live arrival.

  • I led the first unified team of 6+ developers, then the driver (4) and passenger (5) mobile teams. Before moving on, I trained my replacement.
  • I co-led the design system with Product Design. Three teams adopted it, and I built its Storybook for the new passenger app.
  • I moved our releases from Codemagic and CodePush to Expo EAS and GitHub Actions, with staged OTA updates tracked in New Relic.
  • I led the upgrades to Expo SDK 52 and React Native 0.77, and added SonarCloud quality gates that block merges on coverage or quality.
  • I started the new passenger app from scratch in Expo Router, with the full ride flow on Mapbox.

ueno bank

2022 – 2023

A digital bank with about 2.9 million users: login, accounts, cards, transfers, QR payments, and loans.

  • Flutter
  • BLoC
  • Clean Architecture
  • Firebase
App locked

A small working version of the biometric login I built for ueno bank: fingerprint unlock, a secure session, and the home screen.

  • I built the authentication module, with Face ID and fingerprint login, public-key password encryption, and national ID validation.
  • I implemented the OAuth session and the app control layer: forced minimum version, remote maintenance mode, and jailbreak and root detection.
  • I shipped the pre-approved loan flow end to end.
  • I led the in-app rebrand from ueno to ueno bank, and wrote unit, widget, and integration tests.

AI-assisted engineering

I used to write every line myself. Now I interview, spec, delegate and review, and I own what ships.

  1. Interview

    An agent interviews me, one question at a time, before anything is written.

  2. Spec

    Nothing gets built without a design I've read and approved.

  3. Plan

    The plan is small tasks, and each one says how to check it's done.

  4. Build

    Tests first, and "it should work" doesn't count as evidence.

  5. Review

    I read every change before it merges, whoever or whatever wrote it.

This site was built this way: every page started as a spec and a plan.

Experience

  1. Jul 2026 – present

    Technical Lead Frontend

    itti, conto and ubox

  2. Jan 2024 – Jul 2026

    Technical Lead Frontend

    itti, muv

  3. Apr 2022 – Dec 2023

    Senior Engineer / Mobile Developer

    itti, ueno bank and wepa

  4. Jul 2021 – Mar 2022

    Full Stack Developer

    Solumed S.A.

What I work with

Mobile
React Native, Expo, Flutter, native modules
Web
React, Next.js, Vite, shadcn/ui
State and data
Redux Toolkit, Zustand, TanStack Query, Riverpod, BLoC, MMKV
Architecture
Clean Architecture, micro-apps, monorepos, design systems, feature flags
Releases
Expo EAS, GitHub Actions, Codemagic, Firebase App Distribution, OTA, semantic-release
Observability
Sentry, Crashlytics, New Relic, Amplitude, Braze
Quality
TDD, Jest, Testing Library, Appium, WebdriverIO, Flutter Test, SonarCloud, Storybook
Integrations
Mapbox, Google Maps, WebSockets, ML Kit, VisionKit, biometrics, OAuth
Applied AI
Cursor, Claude, GitHub Copilot, Figma MCP, agent skills, spec-driven development
Backend (basic)
REST APIs, PHP, MySQL, Firebase

About

Outside work I play Geometry Dash, Clone Hero, and whatever's on my PC. I'm into psychology, and I work out and run, usually with electronic music, alternative rock, or a podcast playing. I also spend more free time than I should trying new AI tools. And I have 3 cats.

Spanish is my native language. I read and write technical English every day: specs, code review, and docs. My spoken English is intermediate and getting better.

Let's talk

I'm open to tech lead and senior mobile or frontend roles. If you're building a mobile or web product and want someone to take it to production and grow the team around it, email me. I care about the team as much as the product.

Based in Paraguay (UTC−3).

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