Diego Ferreyra, Developer in Córdoba, Cordoba, Argentina
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Diego Ferreyra

Full-stack Developer

Córdoba, Cordoba, Argentina

Toptal member since January 24, 2013

Bio

Diego is a senior Angular developer with 13+ years building production web applications across healthcare, hospitality, and biotech. He specializes in Angular (AngularJS through 18+) and full-stack JavaScript with Node.js and REST APIs, and has shipped work for Royal Caribbean, Ricoh, ADS Environmental Services, and Sage Bionetworks. His recent work includes a HIPAA-compliant healthcare platform and contributions to Cline, an open-source AI coding agent.

Portfolio

Cline Bot Inc.
GitHub, GitHub CLI, TypeScript, JavaScript, Community Management, Node.js...
Stealth Technology Startup
Angular, CSS, Git, CSS3, HTML5, Figma, REST APIs, RESTFul APIs, HIPAA...
Ricoh Corporation - DSC - PortfolioSoftwareSolutions
Angular, Tailwind CSS, Large-scale Projects, Git, Dashboards, Cypress, CSS...

Experience

  • JavaScript - 14 years
  • REST APIs - 10 years
  • RxJS - 8 years
  • Angular - 8 years
  • TypeScript - 8 years
  • AngularJS - 6 years
  • Full-stack - 6 years
  • Node.js - 6 years

Preferred Environment

Visual Studio, MacOS, GitHub, Git, NPM, Node.js, Slack, Figma, Chrome DevTools, GitHub Actions

The most amazing...

...thing I've built is an Angular and D3.js visualization helping Sage Bionetworks researchers prioritize Alzheimer's drug targets from complex biological data.

Work Experience

Technical Support Engineer

2025 - 2026
Cline Bot Inc.
  • Managed technical triage and community operations for a large open-source GitHub repository, helping reduce backlog noise and improve routing of incoming issues, support requests, and feature suggestions.
  • Reviewed and categorized high volumes of GitHub issues and pull requests, separating actionable bugs from support cases, stale reports, duplicates, and feature requests to keep engineering attention focused on high-impact work.
  • Contributed to reducing the open issue backlog to under 350 issues by closing stale or non-actionable reports, requesting missing reproduction details, and improving issue hygiene across the repository.
  • Identified root causes in reported issues through code-level investigation, helping distinguish product defects from environment-specific limitations, expected behavior, or unsupported configurations.
  • Supported contributor and maintainer workflows by refining triage processes, reducing ambiguity in issue handling, and making community-reported problems more actionable for the engineering team.
  • Reported weekly progress using measurable output, including dozens of issues triaged and closed, backlog decisions, and root causes identified.
Technologies: GitHub, GitHub CLI, TypeScript, JavaScript, Community Management, Node.js, React, Artificial Intelligence (AI), AI Pipeline, AI-generated Code, GitHub Actions, Full-stack, Chrome DevTools, Object-oriented Programming (OOP)

Angular Developer

2025 - 2025
Stealth Technology Startup
  • Developed and integrated RESTful APIs with a responsive Angular front end, enabling real-time synchronization between patient and provider management modules.
  • Transformed Figma UI/UX designs into a fully responsive, production-ready web application used by over X patients and healthcare professionals.
  • Collaborated with cross-functional teams (back-end, design, QA) to align API contracts, ensure scalability, and maintain a consistent design system.
  • Implemented new features such as appointment scheduling, medical records display, and authentication flows, improving user satisfaction and engagement.
  • Resolved critical bugs and UI inconsistencies across multiple modules, achieving a significant reduction in reported defects post-release.
  • Maintained code quality standards through linting, reusable components, and peer reviews, improving long-term maintainability of the codebase.
Technologies: Angular, CSS, Git, CSS3, HTML5, Figma, REST APIs, RESTFul APIs, HIPAA, Web Development, Healthcare, Minimum Viable Product (MVP), GitHub CLI, Responsive UI, Front-end, RxJS, Angular Component Architecture, Chrome DevTools, Object-oriented Programming (OOP)

Angular Developer

2024 - 2024
Ricoh Corporation - DSC - PortfolioSoftwareSolutions
  • Developed an app for reviewing scanned rejected checks and allowing the completion of missing information or further rejecting it before the batch gets to the destination.
  • Integrated the app with Ricoh platform services and management.
  • Integrated the app with Mavro systems for check batch details reviewing, image processing, and report selection.
  • Helped with environment and continuous integration development.
Technologies: Angular, Tailwind CSS, Large-scale Projects, Git, Dashboards, Cypress, CSS, CSS3, HTML5, REST APIs, RESTFul APIs, Web Development, CI/CD Pipelines, GitHub CLI, Front-end, RxJS, Angular Component Architecture, Chrome DevTools, Object-oriented Programming (OOP)

Angular Developer

2023 - 2024
Royal Caribbean
  • Collaborated with the engineering and design teams to enhance the user experience of Royal Caribbean’s online booking platform, improving usability and navigation across multiple user journeys.
  • Developed and deployed new Angular components and modules that streamlined travel management and booking flows, resulting in a faster and more intuitive customer experience.
  • Resolved high-priority bugs and optimized performance, ensuring a stable and error-free interface for thousands of daily users.
Technologies: Angular, Cypress, REST APIs, CSS, Git, CSS3, HTML5, Figma, RESTFul APIs, HIPAA, Web Development, GitHub CLI, Responsive UI, Front-end, RxJS, Chrome DevTools, Object-oriented Programming (OOP)

Front-end Angular Developer

2023 - 2023
Random Games Company, Inc
  • Merged five separate Angular apps into a single app for a streamlined single-page application (SPA) deployed in one environment.
  • Tracked and resolved bugs using their reporting system.
  • Refactored components and upgraded login authentication to support the latest blockchain wallet handlers.
Technologies: Angular, HTML, CSS, REST, TypeScript, Git, CSS3, HTML5, REST APIs, RESTFul APIs, Web Development, Real-time Data, Minimum Viable Product (MVP), CI/CD Pipelines, GitHub CLI, Front-end, RxJS, Angular Component Architecture, Chrome DevTools, Object-oriented Programming (OOP)

Web UI Developer

2020 - 2023
ADS Environmental Services / IDEX Corp.
  • Developed new features and optimized existing code using Angular.
  • Identified and fixed bugs with the Jira tracking tool.
  • Supported QA testing and refactored the entire application for improved performance.
Technologies: TypeScript, JavaScript, Angular, Highcharts, Large-scale Projects, Git, CSS, CSS3, HTML5, REST APIs, RESTFul APIs, Web Development, Real-time Data, Front-end, RxJS, Chrome DevTools, Object-oriented Programming (OOP)

Web UI Developer

2020 - 2023
IDEX
  • Developed core features for a web application that puts critical data at your fingertips to support management, engineering, and operational decisions within the wastewater collection system.
  • Tracked and fixed bugs using the Azure tracking environment.
  • Collaborated with the back-end engineers to connect and improve the API.
Technologies: Highcharts, JavaScript, TypeScript, Angular, GitHub, Front-end Development, REST APIs, Material Design, Front-end Architecture, Large-scale Projects, Git, Data Visualization, CSS, CSS3, HTML5, RESTFul APIs, Web Development, Real-time Data, Front-end, RxJS, Chrome DevTools, Object-oriented Programming (OOP)

Angular Engineer

2020 - 2020
AssetWorks
  • Optimized maps for real-time marker updates and tracking for over 5,000 entities.
  • Combined markers to show more advanced information, like type and direction, while moving.
  • Improved and optimized components to avoid issues and help readability.
  • Solved several performance issues with the company's Angular app.
Technologies: Angular, Material UI, Google Maps API, GitHub, TypeScript, Front-end Development, Front-end Architecture, Git, Data Visualization, GIS, CSS, CSS3, HTML5, Google Maps, REST APIs, RESTFul APIs, Web Development, Real-time Data, Front-end, RxJS, Node.js, Chrome DevTools, Object-oriented Programming (OOP)

Front-end Angular Developer

2019 - 2020
Stayafloat
  • Handled all front-end development on a pre-started project and continued working and improving on it as the single developer.
  • Improved the site to be mobile-first ready. Made sure all templates worked on tablets and phones.
  • Created a small JSON parser for dynamic form creations.
Technologies: Angular, Bootstrap, GitHub, TypeScript, Front-end Development, Material Design, Responsive Design, Front-end Architecture, Bootstrap 4, Git, CSS, CSS3, HTML5, REST APIs, RESTFul APIs, Web Development, Real-time Data, Minimum Viable Product (MVP), Marketplaces, Responsive UI, Front-end, RxJS, Angular Component Architecture, Chrome DevTools, Object-oriented Programming (OOP)

Front-end Developer

2018 - 2019
Sage Bionetworks
  • Developed and maintained the site using Angular 7.
  • Built a force chart in D3 for gene network viewing.
  • Developed and optimized a bar chart in DC for gene RNA values.
  • Stored the gene network in MongoDB with Express.js API management.
  • Processed data transforming gene links into force network data.
Technologies: Angular, DC.js, D3.js, MongoDB, Node.js, GitHub, Front-end Development, REST APIs, Material Design, Responsive Design, Front-end Architecture, Git, CSS, CSS3, HTML5, RESTFul APIs, HIPAA, Web Development, Healthcare, Responsive UI, Front-end, RxJS, Chrome DevTools, Object-oriented Programming (OOP)

Full-stack JavaScript Developer

2017 - 2018
Trinity Mobile Networks
  • Optimized Google Maps to host and update 10,000+ markers in real time.
  • Developed several AngularJS features on the main portal.
  • Implemented portal unit testing with Mocha and Chai.
  • Implemented an ES6 transpiler for the AngularJS portal.
Technologies: Google Maps, Node.js, AngularJS, GitHub, REST APIs, Material Design, Git, GIS, CSS3, RESTFul APIs, Web Development, CSS, Front-end, Full-stack, Chrome DevTools, Object-oriented Programming (OOP)

Ionic Developer

2017 - 2017
Visio Green (via Toptal)
  • Developed the application from scratch, choosing to implement ES6 into an Ionic project that come out to worked really well and take advantage of it.
  • Developed the project and its architecture from scratch.
  • Turned wireframes into screens.
  • Optimized information management across the platform.
Technologies: Firebase, ECMAScript (ES6), AngularJS, Ionic, GitHub, REST APIs, Responsive Design, Git, CSS3, Full-stack, Minimum Viable Product (MVP), CI/CD Pipelines, Front-end, Chrome DevTools, Mobile Development, Object-oriented Programming (OOP)

Senior Front-end Developer

2016 - 2016
Lystnr.com (via Toptal)
  • Developed a pixel-perfect landing page.
  • Added new features to the AngularJS app, turning links into editable fields.
  • Added new endpoints to the AngularJS app.
  • Created new form templating.
Technologies: CSS, HTML5, AngularJS, Front-end Development, Responsive Design, Git, CSS3, Minimum Viable Product (MVP), Responsive UI, Front-end, Chrome DevTools, Object-oriented Programming (OOP)

Front-end Developer

2016 - 2016
Pampered Chef (via Toptal)
  • Developed several apps in Angular 2.
  • Improved templates for the client's main site in HTML5 and CSS.
Technologies: Angular, Webpack, ECMAScript (ES6), GitHub, TypeScript, Front-end Development, Material Design, Responsive Design, Git, CSS3, CSS, Responsive UI, Front-end, Chrome DevTools, Object-oriented Programming (OOP)

Full-stack Developer

2016 - 2016
Heal (via Toptal)
  • Developed the client's portal web app from scratch.
  • Set the architecture for the new AngularJS site.
  • Turned wireframes into a working site.
  • Helped with some UI/UX decisions.
Technologies: AngularJS, JavaScript, GitHub, Responsive Design, Git, CSS3, HIPAA, Full-stack, Healthcare, CSS, Responsive UI, Front-end, Chrome DevTools, Object-oriented Programming (OOP)

Full-stack Developer

2015 - 2016
Fapl (via Toptal)
  • Worked along the CEO developing the main site and mobile app.
  • Helped with the back-end implementation, suggesting and researching better and more secure methods.
  • Implemented a secure file upload with Amazon S3.
  • Developed several sections of the mobile and web app, which were both based in AngularJS.
Technologies: Amazon S3 (AWS S3), Express.js, Node.js, Ionic, AngularJS, GitHub, Responsive Design, Git, CSS3, Full-stack, CSS, Front-end, Chrome DevTools

Web Developer

2015 - 2015
Monsoon
  • Used new frameworks like AngularJS and Ember.js.
  • Specialized in CSS and responsive design.
Technologies: JavaScript, GitHub, Front-end Development, Responsive Design, CSS, Front-end, Chrome DevTools

Full-stack JavaScript Developer

2014 - 2015
Kidozen
  • Worked with a Node.js back end for managing connectors and on the front-end side with a custom JavaScript framework. Got the opportunity to contribute to an ACE editor while working on Kidozen.
Technologies: JavaScript, REST APIs, Full-stack, CSS, Mobile Development

JavaScript Developer

2012 - 2013
Motorola
  • Worked with a custom framework.
  • Had a great experience working in an Agile environment.
  • Led the team and interviewed new developers.
Technologies: JavaScript, CSS

Mobile Developer

2011 - 2012
Blanco Martin & Assoc.
  • Designed and developed a number of Android and iOS mobile apps using HTML5.
  • Implemented a RESTful API during development of the apps.
  • Made UI/UX design decisions.
Technologies: JavaScript, CSS3, HTML5, Mobile Development

UI Developer

2011 - 2012
Globant
  • Developed a one-page JavaScript application for Intel AppUp using several different frameworks, including Ember.js, YUI, Backbone.js, and Node.js for the back end.
  • Created a travel web page for AmEx using JavaScript, HTML5, and Ruby. The site included a vacation planning page, which gives users the option of booking hotels, flights, cars, and various travel packages.
  • Developed SKL, a flash cards game for Facebook. Wrote the interface and data management aspects using ActionScript 3.
Technologies: CSS3, HTML5, JavaScript, CSS

ActionScript 3 Developer

2006 - 2010
MindSmack
  • Developed a number of highly interactive sites and games using Flash, including RPG, action, and graphic adventure games.
  • Created an entire ActionScript 3 framework for isometric games.
  • Designed and coded several websites using HTML, CSS, and JavaScript.
Technologies: ActionScript 3, Mobile Development

Web Developer

2003 - 2005
TecnoImagen
  • Built dynamic websites from scratch using Flash and XML for several companies.
Technologies: Microsoft Access

Experience

Water Collection Systems Data Collection and Analysis

I spent over three years developing an app using the latest Angular framework. I created new features and did bug fixing and optimizations on an ever-growing app that included GIS maps, charts, and a lot of data analysis tables.

StayAfloat

I was the solo front-end developer responsible for creating and maintaining the entire site. The application was built using Angular 6 and Bootstrap for mobile-ready functionality. The app consists mainly of a stock-like chart for the offering and demand of tax credits.

Agora

https://agora.ampadportal.org/genes
Angular application for the studies of brain genes related to Alzheimer's.
It was a MEAN stack app. I helped develop the app in general and completely designed and deployed the network widget, which required distilling a complex set of relationships into an understandable view of a candidate ad target.

Heal | Front-end Engineer

https://patient.heal.com/
I developed the front end of a patient portal from scratch using AngularJS. They introduced me to the John Papa Angular style guide, which was really interesting and helped improve my skills. Also, I developed all the UIs to meet their needs.

Fapl, Co.

I joined FAPL as part of the founding development team during the early stages of product design and prototyping. FAPL aimed to revolutionize the fashion industry through a cross-platform web and mobile marketplace that connected quality fashion brands directly with consumers, creating a dynamic and community-driven discovery experience.

Working closely with the CEO and the founding engineers, I contributed to defining the technical architecture and user experience for both the web and mobile applications. I played a key role in transforming product concepts and Figma designs into functional, responsive user interfaces built with Angular.js, Ionic, and Bootstrap, ensuring design fidelity and optimal usability across devices.

Pampered Chef

Worked on several projects with Angular 2. I was new to that technology, but learned a lot during the process.

I also helped on templates to improve the main site.

Lystnr

Developed the new landing page and added new features to the existing Angular app.

Fareness

Developed on AngularJS and built responsive adaptations.

Swyp Card

Developed the landing page.

Intel AppUp

I was involved in the development of several Intel AppUp prototypes. This involved implementing an MVC design and writing APIs using Node.js and MongoDB. I also wrote code for the front end using the Ember, YUI, and Backbone.js frameworks. Additional work included a number of UI/UX bug fixes, as well as using Redmine to track and address bugs in the code.

AmEx Travel

https://travel.americanexpress.com/home
I wrote the front-end UI for the travel portion of the AmEx website using JavaScript, HTML5, and CSS3. Its features include infinite scrolling for hotel search results as well as an API for the Ruby back end.

To-do App | Backbone and SlimPHP Framework

This project features a user-friendly to-do app that uses Backbone.js on the front end and the SlimPHP framework for the API and back-end services, creating a well-structured, user-friendly, and high-performance application.

MindSmack Madness

This is a high definition company promotion website that behaves like an interactive movie. I was the sole developer on the project and implemented an object-oriented approach in ActionScript 3 that included lazy loading, preloading, and video streaming features.

Polaner

This is a website for which I wrote the front-end code using HTML5, CSS3, and Flash.

Ortega

This is a web page for cooking recipes that I developed using Flash, ActionScript, and an XML parser.

Portal Vecino

This is an Android and iOS mobile app that I developed from scratch using PhoneGap with HTML5, CSS3, and JavaScript. It uses a SugarCRM back end and allows users to upload road traffic tips. It also includes a geolocation feature.

Education

2004 - 2007

Bachelor's Degree in Multimedia Design

La Metro - Cordoba, Argentina

Skills

Libraries/APIs

jQuery, RxJS, Google Maps, Highcharts, Google Maps API, Node.js, D3.js, Google Maps JavaScript API 3, Google Maps API (GeoJSON), REST APIs, DC.js, Handlebars, JavaScript API for Chrome, React, Stripe, Stripe API, NgRx, NgRx/store

Tools

Git, Slack, Gulp, Bitbucket, GitHub, NPM, Confluence, Webpack, Sublime Text, Angular CLI, Atom, Grunt, Mercurial, GitHub CLI, Microsoft Access, Visual Studio, Jira, Adobe Photoshop, Adobe Illustrator, Sketch, AWS CodeCommit, Pixelmator, Figma, GIS

Languages

SCSS, CSS, Sass, CSS3, JavaScript, HTML5, HTML, ECMAScript (ES6), TypeScript, Less, ActionScript 3

Frameworks

Bootstrap 3+, Bootstrap 3, Bootstrap, AngularJS, Angular, Angular Material, Material UI, JavaScript MVC, Ionic, Express.js, Next.js, Tailwind CSS, Cypress, Svelte

Paradigms

Agile Software Development, Responsive, Object-oriented Programming (OOP), BEM, Event-driven Programming, Unit Testing, Search Engine Optimization (SEO), Asynchronous Programming, Design Patterns, Mobile Development, Prototype-based OOP, REST

Platforms

MacOS, Firebase, Azure

Storage

JSON, Amazon S3 (AWS S3), MongoDB, MySQL, SlimPHP

Industry Expertise

Healthcare, Photography

Other

Angular Bootstrap, Vine API, Mega, Front-end, Front-end Development, Large-scale Projects, RESTFul APIs, Web Development, Chrome DevTools, Cordova, Angular Component Architecture, Full-stack, Google Maps Styling, APIs, API Integration, Data Visualization, Material Design, Responsive Design, Front-end Architecture, Responsive UI, HIPAA, Real-time Data, Minimum Viable Product (MVP), Artificial Intelligence (AI), CI/CD Pipelines, PSD to HTML, Yam, Illustration, Web UI, Bootstrap 4, Visualization, Dashboards, Community Management, AI Pipeline, Marketplaces, AI-generated Code, GitHub Actions

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