Julien Delort, Developer in Toronto, ON, Canada
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Julien Delort

Verified Expert  in Engineering

Front-end Developer

Toronto, ON, Canada
Toptal Member Since
November 4, 2020

Julien has 15 years of experience as a software engineer with a passion for building full-stack apps. He especially shines in designing and building innovative user interfaces. Julien has a deep knowledge of React and loves finding UI solutions using CSS. His experience includes a software engineer role with Amazon for three years, where he got to work on various full-stack projects, both back end and front end, and he became the "go-to" person for front-end work and advice.


React, Next.js, TypeScript, React Server Components, Social Media APIs, ETL...
Next.js, React, Prisma, PostgreSQL, Tailwind CSS, HTML Email, Message Queues...
TypeScript, React, UI Components, Design Systems, Front-end Development...




Preferred Environment

JavaScript, Node.js, React, Svelte, Front-end, Next.js, TypeScript, Tailwind CSS, HTML, CSS

The most amazing...

...thing I've done was leading the modernization of the front-end stack of a SaaS company from Backbone.js to React and guiding the team on best practices.

Work Experience

Full-stack Next.js Engineer (via Toptal)

2024 - 2024
  • Created an onboarding flow for new users, consisting of multiple consecutive screens, each saving data to the back end via Next.js Server Actions.
  • Focused on the creation of multiple cron jobs (using Inngest) to retrieve and save data from various social media APIs (Facebook/Instagram, YouTube, TikTok, X, Twitch) and upload retrieved images and videos from posts to Cloudflare.
  • Created multiple ETLs to import data from different sources (an FTP server, Amazon S3).
  • Supported the team in the complete rewrite of the product on a Next.js and event-based stack using Inngest.
Technologies: React, Next.js, TypeScript, React Server Components, Social Media APIs, ETL, Cloudflare, Drizzle, MySQL, PlanetScale, Clerk, Tailwind CSS

Senior Full-stack Engineer

2024 - 2024
  • Created a monthly email report (around 70,000 emails/month) that includes a large amount of data presented in charts (bar/pie/line charts).
  • Queried data using Prisma/PostgreSQL, built the email UI using React Email and Tailwind, and used BullMQ to queue emails. Created a monthly email report (around 70,000 emails per month) that includes a large amount of data presented in bar, pie, and line charts.
  • Revamped existing system and marketing emails to be Outlook-compatible (React Email and Tailwind CSS).
  • Guided the team on the usage of React Server Components in Next.js as well as forms and server actions.
  • Fixed some UI, UX, and accessibility issues in the application and refactored some of the form components.
Technologies: Next.js, React, Prisma, PostgreSQL, Tailwind CSS, HTML Email, Message Queues, SendGrid API, APIs, TypeScript, Chart.js, Front-end Development, Code Review, Software Architecture, React Server Components

Senior Front-end Engineer (via Toptal)

2023 - 2024
  • Redesigned existing design system components following the design team guidelines (React).
  • Collaborated with the design team to build new React components and define requirements.
  • Built prototypes to migrate the front-end build from Webpack to Vite and esbuild.
Technologies: TypeScript, React, UI Components, Design Systems, Front-end Development, UI Design, Code Review

Senior Full-stack Engineer | Tech Lead | Staff Engineer

2020 - 2023
Pixlee TurnTo
  • Led the migration from Backbone.js to React and TypeScript. I advocated for this change by building multiple prototypes based on my initiative to show feasibility and benefits. Set up the React stack and mentored the team on best practices.
  • Created and published an npm library to share standard React code amongst projects.
  • Managed several full-stack React projects involving multiple developers and interactions with product and design teams.
  • Created and published an npm library of web components for the design system, introduced the concept to the company, and advocated for its benefits. I built the library's foundations and oversaw the components' development.
  • Modernized the technical stack within the 1st month of joining the team by supporting ES6 and Webpack and introducing front-end unit tests with Jest, improving codebase maintainability and developer experience.
  • Converted a big chunk of the codebase to TypeScript.
  • Created an integration with the Shopify API, allowing brands to send products from their store to influencers in the context of influencer campaigns.
Technologies: JavaScript, Ruby on Rails 5, Backbone.js, React, APIs, Ruby on Rails (RoR), Full-stack, PostgreSQL, SQL, HTML, jQuery, NPM, Jest, Styled-components, React Query, Git, TypeScript, User Interface (UI), React Native, Project Management, Startups, Architecture, Web Development, CSS3, API Integration, User Experience (UX), Technical Leadership, HTML5, CI/CD Pipelines, Storybook, Web UI, Web UX, Design Systems, UI Components, Front-end Development, UI Design, Code Review, Software Architecture, Shopify API, Shopify

Software Development Engineer II

2017 - 2020
  • Designed and co-created the front end for a custom CRM web app, integrated within an existing portal using micro front-end principles. Developed in TypeScript, with React, Redux, and styled-components.
  • Created a contact information management end-to-end feature (database, back end, and front end in React) for a CRM web app. It gathers existing contacts, adds and removes contacts, and tags them, like do not disturb or preferred.
  • Co-created a PR and legal approval workflow for global survey questions. Worked on a back-end serverless service using AWS Lambda, Node.js, and TypeScript and created the front end by myself using React.
Technologies: Lodash, JavaScript, AWS Lambda, Amazon DynamoDB, CSS, Redux Thunk, Node.js, Java, TypeScript, Styled-components, Redux, React, REST, APIs, REST APIs, Full-stack, Express.js, HTML, AWS SDK, Jest, Enzyme, Git, Amazon Web Services (AWS), User Interface (UI), Project Management, Architecture, Web Development, Microservices, CSS3, API Integration, User Experience (UX), Technical Leadership, HTML5, React Redux, CI/CD Pipelines, Web UI, Web UX, Front-end Development, UI Design, Code Review, Software Architecture

R&D Software Engineer

2012 - 2017
  • Co-created from scratch a JavaScript framework to build and display dashboards based on customizable widgets (Vanilla JS, CSS, HTML, C# ASP.NET MVC). Created a web WYSIWYG designer app for users to build such dashboards.
  • Created from scratch, using Vanilla JS, a data-table display library with advanced features like infinite scroll, column resizing, filtering, sorting, and inline editing.
  • Trained the engineering team in France and the US on the usage of the dashboard framework, the designer tool, and the data-table library.
Technologies: JavaScript, C#.NET, ASP.NET MVC, CSS, Vanilla JS, C#, HTML, jQuery, SQL, User Interface (UI), Web Development, CSS3, User Experience (UX), Technical Leadership, HTML5, Web UI, Web UX, APIs, Front-end Development, UI Design

Software Engineer

2009 - 2012
  • Developed and maintained the application developed by the company (video streaming, recording, playback, motion detection, alarm management, and user profile management.) Oversaw the technical choices, architecture, and change tracking.
  • Redesigned the video playback module (WPF, C#, and DirectShow) to make it more modern and more intuitive.
  • Set up an SQL server database for the management of video recordings. Used data virtualization (WPF), which resulted in an instant search of video recordings, which previously took between tens of seconds to several minutes.
  • Designed an algorithm (C#) to precisely manage recording disk space. Created a virtual disk space regrouping all available disk partitions. Added support for NAS servers. The maximum disk space was multiplied by five.
  • Created an automatic update system through the Internet (C#, PHP, MySQL, Ajax, and JQuery), leading to reduced travel costs for technicians.
  • Created an automated build system (C#) for our release build/process, which used to be manual, that removed build-related bugs.
Technologies: C#, C#.NET, C++, Windows Forms (WinForms), Visual Basic 6 (VB6), Windows Presentation Foundation (WPF), SQL, User Interface (UI)

Informel: Forms with Superpowers

Web components that wrap HTML forms to get extra features such as:

• Easily obtain form values
• Automatically show validation errors
• Native and custom validation rules
• Easily track form validity state
• Keep track of whether the form is dirty or not
• Auto submission via Ajax call, using action and method attributes

This was published on npm.

Browse4me – Web Scraping Platform

I'm working on a SaaS platform for web scraping, which is currently in progress. This project consists of two main parts:

• The user-facing platform was developed using SvelteKit and TailwindCSS. It's hosted on Vercel, providing a user-friendly interface for defining step-by-step scraping flows or sequences.

• The API for executing these scraping sequences was built with Node.js and Express and used Puppeteer for web scraping. This API is hosted on a Linode server.

The database is hosted on Supabase, contributing to the platform's data management and storage capabilities.


Shoppingify is an app to manage shopping lists. The app allows users to save products for future usage and show statistics about shopping lists over time.

I solved a dev challenge that can be found here, along with user stories:
• devchallenges.io/challenges/mGd5VpbO4JnzU6I9l96x

Donor Wall Data Management App for a Nonprofit

Created a web app to help a nonprofit organization manage the data for their digital donor wall. The web app manages donor names in different sections and tiers, finds duplicates, shows previews, and exports the data so that it can be pasted to the organization's website.

Social-textarea: A React "Social" Textarea Supporting User Mentions, Emojis, and URL Previews

A React "social" textarea that supports user mentions, emojis, and URL previews. The textarea is similar to "Create Post" inputs used on social media platforms, and it also exports an emoji picker button. The component is built on top of react-mentions and emoji-mart and published on npm.

Todo App

Solved a dev challenge that can be found here, along with the design: https://www.frontendmentor.io/challenges/todo-app-Su1_KokOW.

This is a basic to-do list app. The goal of this was to get more familiar with SvelteKit.

Conduit Next.js

This is a mock blogging platform built with the Next.js app router and React Server Components. It allows users to create, read, update, and delete articles. Users can also follow other users and favorite articles. It's a simplified implementation of the Realworld project and is built using the Next.js app router (React Server Components), Prisma, TypeScript, and Tailwind CSS.
2003 - 2008

Master's Degree in Computer Science

National Institute of Applied Sciences (INSA) - Lyon, France


React, Node.js, Lodash, Backbone.js, jQuery, React Query, React Redux, Chart.js, REST APIs, Windows Forms (WinForms), Puppeteer, SendGrid API, Shopify API, Social Media APIs, Drizzle


Redux Thunk, AWS SDK, NPM, Prisma, Git


Vanilla JS, Next.js, Express.js, Svelte, Redux, Tailwind CSS, ASP.NET MVC, Ruby on Rails 5, Ruby on Rails (RoR), Windows Presentation Foundation (WPF), Jest, Remix, React Native


JavaScript, CSS, TypeScript, HTML, SQL, CSS3, HTML5, Java, C#.NET, C#, C++, Visual Basic 6 (VB6)


REST, Microservices, UI Design, ETL


AWS Lambda, Firebase, Amazon Web Services (AWS), Vercel, Linode, Shopify, PlanetScale, Clerk


Amazon DynamoDB, PostgreSQL, MongoDB, MySQL

Industry Expertise

Project Management


Styled-components, Front-end, APIs, Full-stack, User Interface (UI), Web Development, User Experience (UX), Technical Leadership, Web UI, Web UX, Design Systems, UI Components, Front-end Development, Code Review, Startups, Architecture, API Integration, Scraping, Web Scraping, Software Architecture, React Server Components, Web Components, Forms, Enzyme, SvelteKit, Supabase, CI/CD Pipelines, Storybook, Software Development, IT Project Management, HTML Email, Message Queues, Cloudflare

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