Sergio Castillo Yrizales, JavaScript Developer in Lima, Callao Region, Peru
Sergio Castillo Yrizales

JavaScript Developer in Lima, Callao Region, Peru

Member since January 10, 2014
Sergio is a top JavaScript developer with extensive experience in both front-end (AngularJS and Backbone) and back-end (NodeJS, Express, and Socket.IO). He is strong both as an individual developer and as part of a team.
Sergio is now available for hire




Lima, Callao Region, Peru



Preferred Environment

Subversion (SVN), Git, Sublime Text, MacOS, Linux

The most amazing...

...application that I've developed is a web crawler that reads and processes diverse financial information, calculates indicators, and stores in three databases.


  • JavaScript Developer

    2016 - 2017
    • Developed a Google Maps plugin for grouping markers and smooth interaction.
    • Developed an infinite scroll for specific needs in Angular.
    • Improved user input components for capturing geographical data.
    • Decreased calls to the server using local storage.
    • Simplified testing with Redux and React on the new components.
    Technologies: React, Angular, AngularJS
  • Front-end Developer

    2015 - 2016
    • Built a video player based on YouTube, Vimeo, Vine, and some other platforms.
    • Added social features like comments and a voting system.
    • Enabled uploading of images and videos through the web.
    • Deployed tasks for SEO content generation.
    • Added responsive design to every page to allow for viewing on any device.
    Technologies: AngularJS, JavaScript
  • Front-end Developer

    2015 - 2015
    • Created a web music player with continuous playing over a playlist.
    • Added social features based on a Ruby back-end.
    • Integrated with SoundCloud for music search.
    • Added tests through Jasmine using Angular Mocks.
    • Implemented automatic deployment tasks using Grunt.
    Technologies: AngularJS, JavaScript
  • JavaScript Developer

    2014 - 2014
    • Defined new components for improved user experience on the site.
    • Built a web app generator based on rules.
    • Created a graphic representation of a graph database.
    • Integrated with Google Drive and Google OAuth.
    • Implemented custom IntelliSense on the ACE Editor.
    Technologies: Node.js, AngularJS
  • Senior Software Developer

    2013 - 2014
    Belatrix Software Factory
    • Built a web app for handling the management process for advertisement videos in order to maximize impression on customers.
    • Investigated best practices for AngularJS development.
    • Maintained a hedge management application.
    • Taught my fellow coworkers how to take advantage of AngularJS.
    • Investigated and researched new HTML5 technologies like WebRTC, WebWorkers, and WebSockets.
    Technologies: Backbone.js, AngularJS, Node.js
  • Web Developer

    2011 - 2013
    • Built a cross-platform tool for survey taking and graphical reporting.
    • Built a business analysis tool for information from surveys.
    • Built an exchange platform for Supply Change Management.
    • Supported the migration of data.
    • Researched new mobile alternatives to Android.
    Technologies: Backbone.js, jQuery Mobile, .NET
  • Web Developer

    2009 - 2011
    • Built a web platform for online shopping.
    • Upgraded a logistics web app.
    • Upgraded a sales web app to deliver a better user experience.
    • Built a dashboard to offer a quick overview of the critical areas of the enterprise.
    • Built an AJAX framework to implement a better user experience in different applications.
    Technologies: jQuery, .NET
  • Software Developer

    2008 - 2009
    • Constructed a web crawler for collecting assorted financial information.
    • Migrated programs from Progress 4GL to .NET.
    • Maintained a credit management desktop application.
    • Built a DLL for communication from a .NET app to exposed routines from SAP.
    • Built a web services application for handling all the communication with a SAP server.
    Technologies: ABAP, PL/SQL, .NET


  • RealMassive

    Site for searching and managing real estate sales, leases, and subleases

  • Winnin

    Video battles site for choosing the best videos related to a topic.

  • Echo Application

    A web application for a social music playlist.

  • Advertisement Platform

    I have been a part of the entire development process for this application. It has allowed me to become proficient in good practices for AngularJS and JavaScript.

  • Toptal Mentor
    Sergio 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. Sergio 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

    JavaScript, HTML5, C#, ABAP, Ruby
  • Frameworks

    AngularJS, Redux, Angular, ASP.NET MVC 4, .NET
  • Libraries/APIs

    jQuery, Backbone.js, React, Node.js, jQuery Mobile
  • Tools

    WebStorm, Subversion (SVN), Sublime Text, Git
  • Paradigms

    Agile Software Development, Design Patterns, Functional Programming
  • Platforms

    Android, MacOS, Linux
  • Storage

    SQL Server 2008, Oracle SQL, Oracle PL/SQL, PL/SQL


  • Bachelor's degree in Software Engineering
    2004 - 2008
    Universidad Nacional Federico Villarreal - Lima, Perú

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