Julien Renaux, Developer in Toulouse, France
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Julien Renaux

Software Developer

Toulouse, France

Toptal member since June 16, 2015

Expertise
GitJavaScriptAngularTypeScriptReduxIonicFirebaseReact.jsjQueryCoffeeScriptApache CordovaNode.jsLinuxPHPHTML5
Bio

Julien is an accomplished full-stack JavaScript engineer with extensive experience developing applications across diverse industries, including space, retail, sports, Web3, eCommerce, and IoT for home gardening, on a global scale. Holding a Scrum Master certification, Julien has effectively collaborated with international teams, contributing to projects for multinational corporations such as eBay and Rakuten, as well as for innovative startups.

Portfolio

FrunkFriends
Supabase, Claude Code, Google Antigravity, Firebase, Android, iOS, Web...
Neptune Cigars
Angular, Capacitor, Progressive Web Applications (PWAs), PWA, Ionic
ForgeRock Open Banking Team
Angular, TypeScript, Cypress, Jest, RxJS, Redux

Experience

  • JavaScript - 9 years
  • Angular - 6 years
  • Node.js - 6 years
  • Ionic - 5 years
  • TypeScript - 5 years
  • Firebase - 4 years
  • React - 4 years
  • Stencil.js - 3 years

Preferred Environment

TypeScript, React, Docker, Web, Claude Code, Google Antigravity, Deno, Node.js, PostgreSQL, Supabase

The most amazing...

...thing was leveraging autonomous AI workflows to simultaneously orchestrate back-end and PostgreSQL DB in Supabase alongside native and web apps at FrunkFriends.

Work Experience

CTO

2026 - PRESENT
FrunkFriends
  • Spearheaded the end-to-end design, architecture, and development of FrunkFriends, a niche social network for EV owners. Managed the entire product lifecycle from concept to launch, delivering a secure, bot-free platform for community engagement.
  • Architected a robust, scalable ecosystem using Supabase and PostgreSQL for the back end. Engineered seamless cross-platform experiences by developing a high-performance native Flutter mobile app and a highly responsive Next.js web application.
  • Established a scalable technical foundation to support data-heavy multimedia sharing, real-time vehicle telemetry, and custom AI integrations. Enforced strict authentication to maintain integrity, successfully deploying a high-engagement platform.
Technologies: Supabase, Claude Code, Google Antigravity, Firebase, Android, iOS, Web, PostgreSQL, Next.js

Lead Front-end Engineer

2020 - 2026
Neptune Cigars
  • Led end-to-end development of multiple cross-platform applications for Neptune Cigar, the U.S. leader in online cigar retail. Built and maintained Cigar Scanner, a high-traffic iOS, Android, and PWA app, serving thousands of cigar enthusiasts.
  • Architected a React/Next.js 15 micro-frontend monorepo (Nx) powering neptunecigar.com's account and checkout apps. Playwright E2E tests, and Storybook component documentation, enabling independent deployment of each storefront module at scale.
  • Built two native tablet/handheld apps: a Point-of-Sale system (Angular/Capacitor, with Socket Mobile hardware integration) and a warehouse order-picker streamlining in-store sales and fulfillment workflows across Neptune Cigar retail operations.
Technologies: Angular, Capacitor, Progressive Web Applications (PWAs), PWA, Ionic

Lead Front-end Engineer

2018 - 2020
ForgeRock Open Banking Team
  • Created a white-label open banking sandbox (bank, directory, OAuth, analytics) sold to many banks using an Angular monorepo.
  • Automated builds, tests, and releases using Docker images on GCP.
  • Implemented unit tests with Jest.
  • Implemented E2E tests with Cypress.
Technologies: Angular, TypeScript, Cypress, Jest, RxJS, Redux

Lead Front-end Engineer

2017 - 2018
CDX Limited (Cryptocurrency Exchange)
  • Architected and designed an IPO web app that raised 10,000 ETH (millions of dollars) and an exchange app with React.
  • Created a design system with hundreds of reusable components.
  • Automated builds, tests, and releases using Docker images.
Technologies: Babel, Webpack, ES7, ECMAScript (ES6), Redux, React

Lead Front-end Engineer

2016 - 2017
Rakuten
  • Architected and designed a gaming web app for the Japanese market using React.
  • Created a design system with hundreds of reusable components.
  • Automated builds, tests, and releases using Docker images.
Technologies: Babel, Webpack, ES7, Emacs, Redux, React

React Software Engineer

2016 - 2016
CNES (French Space Agency)
  • Implemented a performance improvement of an existing React application to support thousands of data points coming live from satellites.
  • Automated builds, tests, and releases using Docker images.
  • Contributed to the React Stockcharts library, the major open-source lib for stocks.
Technologies: Babel, Webpack, ES7, ECMAScript (ES6), Electron, Redux, React

Software Engineer

2012 - 2015
Living Objects
  • Developed a rich JavaScript application using AngularJS, Angular Material, and Node.js.
  • Created a platform that monitors access provider networks using jQuery, CoffeeScript, PHP5 (Symfony2), and Bootstrap 3.
  • Implemented quality processes, including unit tests, merge requests, code review, and CI via Jenkins; led the SVN-to-Git transition.
Technologies: JavaScript, Webpack, jQuery, CSS, HTML, PHP, Node.js

Software Engineer

2010 - 2012
eBay, Inc.
  • Worked on a web analytics platform for internal information sharing (17,000 employees) based on Joomla.
  • Led a multinational team consisting of ten members distributed globally as a Certified Scrum Master.
  • Developed components/modules/widgets for Joomla.
  • Administrated the continuous integration platform using Jenkins.
  • Created the JavaScript framework and UI library used in the project using Vanilla JavaScript.
Technologies: JavaScript, MooTools, CSS, HTML, Joomla, PHP

Experience

Julien Renaux Blog

For years I have been sharing thoughts and tips about front-end engineering.

Also available on Android: https://play.google.com/store/apps/details?id=com.shprinkinc.wordpresshybridclient

Isitblackfridayyet

Every day, get a reminder whether it is Black Friday or not. This product was created as a joke and took the internet by storm!

Learn about the journey and the technologies used on:
https://julienrenaux.fr/2019/11/25/case-study-isitblackfridayyet/
Image of Ionic 2 vs. Ionic 1: Performance Gains, New Tools, and a Big Step Forward publication
Publication

Ionic 2 vs. Ionic 1: Performance Gains, New Tools, and a Big Step Forward

https://www.toptal.com/developers/ionic/ionic-1-vs-ionic-2-key-differences
Image of The 9 Most Common Mistakes That Ionic Developers Make publication
Publication

The 9 Most Common Mistakes That Ionic Developers Make

https://www.toptal.com/developers/ionic/most-common-ionic-development-mistakes

Education

2010 - 2011

Master's Degree in Computer Science, Big Data

Tongji University - Shanghai, China

2006 - 2011

Master's Degree in Computer Science, Programming

Telecom Lille - Lille, France

Certifications

JANUARY 2021 - PRESENT

Santander's Hackathon Winner

Santander

MARCH 2019 - MAY 2021

Google Developer Expert

Google

Skills

Libraries/APIs

React, jQuery, MooTools, Node.js, RxJS, Firebase Web SDK, Facebook API, GitHub API

Tools

Capacitor, Git, Webpack, Jenkins, Babel, Gulp, Stencil.js, Emacs, PostCSS, Claude Code

Languages

TypeScript, CoffeeScript, JavaScript, ECMAScript (ES6), PHP, Sass, Less, HTML5, HTML, CSS, ES7, SQL

Frameworks

Angular, Redux, Ionic, Jest, Jasmine, Electron, Cypress, React Native, PHPUnit, Next.js

Paradigms

Mobile Development, Cross-platform, Scrum

Platforms

Firebase, Android, Linux, WordPress, Joomla, MacOS, Visual Studio Code (VS Code), Web, Docker, iOS

Storage

MySQL, MongoDB, PostgreSQL

Other

Software Development, Single-page Applications (SPAs), Mobile App Development, Hybrid Apps, Cordova, PWA, Front-end, Progressive Web Applications (PWAs), Supabase, Google Antigravity, Deno

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