José Maldonado, Software Developer in Buenos Aires, Argentina
José Maldonado

Software Developer in Buenos Aires, Argentina

Member since July 27, 2015
José is a skilled software developer with a computer engineering degree and experience in web development, mobile apps, and bug fixing. He enjoys learning new technologies, contributing to open source projects, and working on interesting and challenging projects.
José is now available for hire


  • Critical Start
    Git, Docker, Python, Less, Grunt, Flutter, Dart, Express.js, Node.js...
  • Toptal Ops Labs
    Chrome, BigQuery, Elasticsearch, Django, Python, MobX, React, JavaScript
  • Termtegrity (via Toptal)
    Git, Docker, Python, Less, Grunt, React Native, AngularJS, JavaScript



Buenos Aires, Argentina



Preferred Environment

Windows, Git, Sublime Text

The most amazing... I've developed is an immigration control system that was instrumental in uncovering a network of migrant traffickers in Senegal.


  • Software Engineering Manager

    2018 - PRESENT
    Critical Start
    • Developed and maintained a web application for managing incident security alerts.
    • Developed the mobile version of a web application tool.
    • Supported users with issues on both the web and mobile applications.
    • Built an application for managing and running Docker containers.
    • Led a team of UX, front-end and mobile developers.
    Technologies: Git, Docker, Python, Less, Grunt, Flutter, Dart, Express.js, Node.js, React Native, React, AngularJS, JavaScript
  • Full-stack Developer

    2018 - 2020
    Toptal Ops Labs
    • Updated a Chrome extension, developed with JavaScript and React, to add new features.
    • Updated a REST API, developed with Python and Django, to add new endpoints.
    • Implemented a web application, using JavaScript and React, to generate reports.
    Technologies: Chrome, BigQuery, Elasticsearch, Django, Python, MobX, React, JavaScript
  • Front-end Developer

    2017 - 2019
    Termtegrity (via Toptal)
    • Transformed the existing web application into a single-page application.
    • Converted wireframe images into interactive HTML web pages.
    • Implemented a mobile app for Android and iOS using React Native.
    Technologies: Git, Docker, Python, Less, Grunt, React Native, AngularJS, JavaScript
  • Front-end Developer

    2017 - 2018
    Advanced Threat Analytics (via Toptal) [acquired by Critical Start]
    • Developed and maintained the main site, implementing new features as well as detecting and fixing bugs.
    • Developed a mobile application for iOS and Android using React Native.
    • Integrated external services into the main site and in the mobile app.
    • Supported users with issues on the main site.
    • Performed code review and technical analysis.
    • Developed a new CSS theme for the main site.
    Technologies: Git, Docker, Python, Less, Grunt, React Native, React, AngularJS, JavaScript
  • Front-end Developer

    2017 - 2017
    Symphony Commerce (via Toptal)
    • Detected and fixed bugs.
    • Created and improved UI themes.
    • Refactored JavaScript code.
    Technologies: Gulp.js, jQuery, AngularJS, JavaScript, Sass, CSS, HTML
  • Game Developer

    2016 - 2017
    Sabacc Creative (via Toptal)
    • Added new functionalities and fixed bugs to the HTML5-based game.
    • Integrated several services (such as Google Analytics, OneSignal, and Apteligent) to an Apache Cordova app.
    • Developed a real-time server, using WebSockets, to host multiplayer games.
    Technologies:, WebSockets, Node.js, iOS, Android, Cordova, JavaScript, HTML5
  • Lead Developer

    2011 - 2017
    • Developed and maintained IICS, an integrated immigration control system currently being used at several international airports from West Africa.
    • Developed an HTML5 application for employee supervision.
    • Integrated the FIND service from Interpol at airports of the Ivory Coast and Senegal.
    • Designed and implemented software for the management and printing of residence and work permits for the government of Sierra Leone.
    • Managed teams of up to six people using Agile methodologies.
    Technologies: Mercurial, Git, PHP, Sass, Less, CSS, HTML5, CouchDB, MongoDB, Cordova, Node.js, React, AngularJS, jQuery, JavaScript, PostgreSQL, MySQL, Microsoft SQL Server, .NET, C#
  • Full-stack Developer

    2016 - 2016
    RentMyChurch (via Toptal)
    • Converted PSD template images into interactive HTML web pages.
    • Migrated websites.
    Technologies: Git, CSS, Bootstrap, jQuery, JavaScript, PHP
  • Front-end Developer

    2016 - 2016
    Azumio (via Toptal)
    • Developed single-page applications that consumed a REST API.
    • Converted PSD template images into interactive HTML web pages.
    Technologies: Git, Sass, CSS, jQuery, Angular, JavaScript, HTML
  • Full-stack Developer

    2015 - 2016
    Funnel Envy (via Toptal)
    • Designed and implemented unit tests.
    • Discovered, reported, and fixed bugs (in both front and back end).
    • Implemented integration layers between the application and third-party services.
    Technologies: Sails.js, Git, Mocha, Angular, Node.js, JavaScript
  • Front-end Developer

    2015 - 2015
    P4 Global (via Toptal)
    • Integrated and modified (for better integration) an Autocomplete plugin.
    • Integrated and extended (for custom features) a WYSIWYG component.
    • Designed an interactive view for importing Word documents.
    • Integrated a JavaScript file manger with the application's own back-end methods.
    Technologies: Git, Vagrant, CSS, jQuery, JavaScript, Laravel, PHP
  • Front-end Developer

    2015 - 2015
    Conversion Systems (via Toptal)
    • Converted PSD template images into HTML web pages.
    Technologies: jQuery, JavaScript, CSS, HTML
  • Full-stack Developer

    2010 - 2011
    • Designed and implemented a system for managing purchase and work orders for RomiPack.
    • Designed and implemented a web application for managing purchase orders for Delicity.
    • Implemented a human resources management tool for AON.
    • Developed a reservation management app for Rojo Tango.
    Technologies: CodeIgniter, PHP, Android, jQuery, JavaScript, CSS, HTML, PostgreSQL, MySQL, Jakarta EE, Java
  • IT Intern

    2008 - 2009
    Institute of High Voltage and Energy Transmission
    • Developed an application for managing experiments and maintaining the institute's website.
    Technologies: JavaScript, CSS, HTML, MySQL, Java


  • IICS

    Implementation of an immigration control system currently used in several airports in West Africa, which allows for the capture of wanted criminals, detection of tax evaders, and discovery of suspicious travel patterns.

  • Biscuissimo

    Development of a web application for the Tentissimo Group, a coffee house chain with more than 120 locals in Buenos Aires, to simplify the management of sales orders and the estimation of required supplies.

  • SimCo60

    Implementation of a scientific simulation tool for estimating radiation exposure levels, developed for the Semi-Industrial Irradiation Plant (PISI) at the Ezeiza Atomic Center, a facility that provides services of ionizing radiation exposure for sterilization of medical equipment, irradiation of food, and decontamination of cosmetics.

  • Neon Camera

    Development of an Android app that uses computer vision to generate pictures with a "neon lights" effect.

  • Open Source

    Several open-source projects, such as aFileDialog (a file chooser library for Android), ngComboDatePicker (an Angular directive that implements date pickers using combo boxes) and jqScrollAnim (a jQuery plugin for define animations whose reproduction depends on the position of the vertical scroll).

  • "Best Graduates in Engineering Careers" Award

    Award granted by the National Academy of Engineering for being one of the best engineers graduated from an Argentinian university in the year 2009.

  • Why Tech Is Making Us Lonely (And How to Reverse That)

    A short article about the ways in which technology is contributing to making us lonely, and how (as IT workers) we can reverse it.

  • The Art of War Applied To Software Development (Publication)
    The Art of War is an ancient military treatise, but despite its age, the text is still included in the syllabus at many military schools. Sun Tzu’s principles and teachings also have practical applications in politics, business, sports, and, believe it or not, software development. In fact, you might just be applying some of these principles in your daily routine, without even knowing. In this post, Toptal Freelance Software Engineer Jose F. Maldonado explains why many of these ancient teachings still matter, and what you can do to make them work for you and your team.
  • Toptal Mentor
    José is a mentor in the Toptal Global Mentor’s Program. This program is a partnership between Toptal and General Assembly to provide high quality mentorship for students from minority and low income backgrounds who are looking to begin their careers as professional software engineers. José shows commitment to diversity in tech by mentoring a General Assembly student every week for a year, covering everything from coding tips and tricks to advice on making it in the industry.


  • Languages

    CSS, Java, JavaScript, C#, SQL, PHP, Python, HTML5, Dart, Less, Sass, HTML, Ruby, CoffeeScript, Scala, R, TypeScript
  • Frameworks

    AngularJS, .NET, Angular, React Native, CodeIgniter,, ASP.NET, Sails.js, Windows Communication Framework (WCF), Flutter, Laravel, Bootstrap, Express.js, Chrome, Ruby on Rails (RoR), Windows Presentation Foundation (WPF), Django
  • Libraries/APIs

    jQuery, Node.js, Vue.js, React, D3.js, MobX
  • Tools

    Git, Gulp.js, Grunt, Inkscape, Mercurial, Sublime Text, Vagrant, Mocha, BigQuery, Adobe Photoshop, Adobe Illustrator
  • Storage

    PostgreSQL, MySQL, SQLite, MongoDB, Microsoft SQL Server, Oracle 11g, CouchDB, Elasticsearch, AWS S3
  • Paradigms

    MEAN Stack, Agile Software Development, Unit Testing
  • Platforms

    Linux, Jakarta EE, Windows, Android, iOS, Docker, OpenShift, Amazon Web Services (AWS), WordPress, Heroku
  • Other

    Cordova, WebSockets, PWA, Progressive Web Applications (PWA)


  • MicroMasters degree in Data Science
    2019 - 2020
    UC San Diego - United States
  • Certificate in Software Engineering
    2009 - 2009
    University of Technology of Belfort-Montbéliard - France
  • Engineer's degree (summa cum laude) in Computer Sciences
    2004 - 2009
    National University of Tucumán - Argentina

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