Johnathan Hebert, Developer in Cedar Park, TX, United States

Johnathan Hebert

Front-end Developer

Cedar Park, TX, United States
Toptal Member Since
March 19, 2017

Johnathan has 15 years of experience writing web apps that span consumer productivity software to mission-critical financial trading platforms. He has extensive knowledge of front-end JavaScript and browser APIs as well as significant experience with popular frameworks and libraries like React and Redux. Johnathan's deep full-stack experience includes Node.js and Express, MongoDB as well as more traditional technologies like PHP, ASP.NET, and MySQL.

Johnathan is available for hire
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CSS, HTML, JavaScript
D3.js, Redux, React, JavaScript
jQuery, Backbone.js, JavaScript


Cedar Park, TX, United States



Preferred Environment

Chrome Developer Tools, Git, Sublime Text, MacOS, Windows

The most amazing...

...impact I've had with software is writing the rich text editor used by all 200+ million Evernote users.

Work Experience

2012 - PRESENT

Lead Front-End Engineer

  • Led the development of a unified rich text editor that runs on mobile, desktop, and web for 200+ million users.
  • Developed a JavaScript-based image annotation app that runs on desktop and web; it also allows for re-editable PNGs/JPGs by storing vector annotation data in the image binary.
  • Created a feature to present HTML-based pages in a full-screen auto-generated presentation with advanced user controls and layout options.
  • Integrated a build pipelines of 5+ complex applications to reliably use common rich-text editing component.
  • Developed a custom vector graphics library for use in annotating both bitmaps and PDFs.
Technologies: CSS, HTML, JavaScript
2017 - 2017

Front-End and Visualization Developer

  • Created several React components with D3 charts that support interactive visualizations of market data projections and analysis.
  • Developed unit tests and component snapshot tests using Jest and Enzyme.
  • Implemented client-side data transformations to map, filter, reduce, etc. large datasets for display in interactive SVG charts.
  • Supported dynamic forms for providing market data analysis for food and beverage companies making projections about product/factory capacity, cost, and several other factors.
  • Created dynamically populated data filters as dropdowns, checkbox groups, input fields, sliders, etc. in order to evaluate and pivot market data analysis charts.
  • Used Chrome DevTools to investigate and fix front-end rendering performance issues and computationally intensive bottlenecks.
Technologies: D3.js, Redux, React, JavaScript
2015 - 2015

Senior Front-End Engineer

  • Added a Backbone router and state management for complex query navigation pages.
  • Refactored very large front-end application code to make it more modular and reusable.
  • Wrote advanced jQuery DataTables plugins and UX handling.
  • Wrote form-based pages to dynamically change as data was entered and REST API was queried.
  • Developed several filtering UX controls to allow users to quickly enter and review medical spending information.
Technologies: jQuery, Backbone.js, JavaScript
2014 - 2014

Senior Front-End Engineer

  • Developed a streaming music service front-end that allows users to create custom radio stations.
  • Created and optimized AngularJS services, directives, bindings, and event handlers used for radio station user UX.
  • Fixed several bugs and reworked the UI/UX to provide smoother interactions with a web app while music was streaming.
Technologies: Less, CSS, AngularJS, JavaScript
2013 - 2014

Senior Front-End Engineer

  • Handled the heavy development of embedded JavaScript widgets on third-party publisher sites.
  • Worked with nested iframes, asynchronous loading of ads, and sizing/scaling issues for mobile, and error-handling.
  • Created robust ads that reliably loaded, retired, and were gracefully handled in multiple browsers and platforms.
Technologies: JavaScript
2011 - 2012

Senior Front-End Engineer

Sogeti (
  • Developed new shopping and browse application pages where all main shopping traffic visits
  • Implemented a new browse filtering UX for narrowing search results and adding items to cart.
  • Wrote a performance monitoring library to use performance counters for measuring front-end delivery and back-end service responses.
Technologies: ASP.NET MVC, JavaScript
2010 - 2011

Senior Front-End Engineer

Merrill Lynch Commodities
  • Built a desktop-like browser application for real-time analysis of risk and commodity index valuations.
  • Developed dynamic and interactive charting of commodity index data with jQuery and Highcharts.
  • Designed, developed, tested, and released a commodity index market tool used in the valuation and hedge analysis of large commodity index swap, options, futures, and structured note transactions.
  • Created several web services using ASP.NET MVC (C#) and WCF to enable communications with other trading desk applications via REST, SOAP, JSON, and custom XML messages.
Technologies: Python, ASP.NET, Ext JS, JavaScript
2005 - 2010

Senior Software Engineer

INTECSEA Engineering
  • Acted as a software architect and lead developer of an Ext.js browser application—an interface/risk tool for $10 billion Chevron LNG project.
  • Developed a PHP/MySQL framework to build-out custom on-premise deployments of an interface management web application.
  • Led the design, development, and implementation of in-house business management systems using C# and ASP.NET to provide a unified intranet for employees to access the full range of enterprise information.
Technologies: PHP, Microsoft SQL Server, ASP.NET, Ext JS, JavaScript
2002 - 2005

Lead Software Engineer

  • Developed custom websites using PHP, MySQL,and JavaScript.
  • Wrote a framework to generate new custom websites with custom database back-end for improved roll out and prototyping.
  • Converted a traditional web application to a single-page application using AJAX and a state management layer in JavaScript.
Technologies: MySQL, PHP, JavaScript


Evernote Rich Text Editor

A rich text editor written in JavaScript that runs on iOS, Android, Mac, Windows, and the web. The editor makes heavy use of the content-editable technology provided by browsers, and has an impressive structure to guarantee smooth editing on top of multiple platforms. It is reliably used by many millions of Evernote users to improve their productivity every day.

At its core, it is listening for every keystroke and user event coming into the editor and reconciling them into a rendered rich text document that reliably displays the users intent. It does an impressive job of overcoming many browser bugs and limitations that surface when accepting arbitrary HTML input from a variety of sources on a variety of platforms.

Skitch | Evernote

An image annotation app written in JavaScript as well as the custom 2D graphics library that powers it. The application is also bundled into the Evernote applications as an image annotation feature. It makes heavy use of the canvas element, immediate mode graphics, and coordinate transformations to give the user the feel of a modern vector graphics app. The image annotations and manipulations run at a smooth 60 fps and use the best parts of the browser's canvas element to provide a rich addition to images on the web.

Bank of America Commodity Index Online Application

An application available to Bank of America institutions and high-net worth individuals that allows them to price and research commodity indices. The application has an advanced charting and reporting interface on the web that breaks commodity indices down to their constituent parts and shows how the index price is computed. In addition to the front-end display, the back-end is tied into the Bank of America ongoing risk calculation and index positions with investors. It calculates prices in near real-time and streams them to the front-end built in Ext.js.



C++, HTML, CSS, JavaScript, PHP, Less, Python


Redux, Ember.js, Unity, Unity3D, React Native, Express.js, Ext JS, AngularJS, ASP.NET MVC, ASP.NET


TensorFlow, React, React Redux, React Router, Node.js, Backbone.js, jQuery, D3.js


Sublime Text 3, Mongoose, Sublime Text, Git, Chrome Developer Tools


Windows, MacOS


Blockchain Development, Browsers, Front-end, Async.js, Web Development, Content Management Systems (CMS), User Experience (UX), Machine Learning, Software Development, Back-end Development, Freelancing, HTTP, Ajax




MySQL, MongoDB, Microsoft SQL Server


2002 - 2005

Master of Science in Aerospace Engineering

Texas A&M University - College Station, TX, USA

1996 - 2000

Bachelor of Science in Mechanical Engineering

University of Notre Dame - South Bend, IN, USA