Alexandre Mondaini Calvão, Ruby on Rails Developer in Rio de Janeiro - State of Rio de Janeiro, Brazil
Alexandre Mondaini Calvão

Ruby on Rails Developer in Rio de Janeiro - State of Rio de Janeiro, Brazil

Member since October 5, 2012
Alexandre is an expert Ruby on Rails developer who is also experienced with Java and various front-end technologies. In addition, he's worked extensively with WebRTC, building video-based web apps from scratch and many back-end APIs to be consumed by Angular and React.
Alexandre is now available for hire




Rio de Janeiro - State of Rio de Janeiro, Brazil



Preferred Environment

Ubuntu, MacOS

The most amazing... I've developed is an isometric map display created with the Kinect.js framework.


  • Senior backend developer

    2020 - 2021
    Only One, Inc.
    • Built an API from scratch for use with an Angular front-end.
    • Integrated the back end with many technologies like Stripe and Campaign monitor.
    • Worked on the Angular front end to fully support the token authentication system.
    Technologies: Ruby on Rails (RoR), Angular
  • Senior Ruby on Rails Developer

    2019 - 2019
    • Developed many functionalities using Rails-related technologies for both back and front-end.
    • Managed AWS instance servers and created new ones for other environments.
    • Implemented Capistrano to ease the deployment of the application on many servers.
    Technologies: Ruby on Rails (RoR), Unix, AWS
  • Cordova Developer

    2019 - 2019
    • Updated the Rideshare app for both Android and iOS.
    • Updated the Rails back end from Rails 3 to 4 and all required gems.
    • Created new functionalities on the active admin dashboard.
    Technologies: Cordova
  • Software Developer

    2019 - 2019
    One Love
    • Created a fully responsive website using Bootstrap.
    • Managed a DigitalOcean server with Capistrano and related technologies.
    • Developed back-end features in Rails using the ActiveAdmin gem.
    Technologies: Capistrano, Bootstrap, CoffeeScript, Ruby on Rails (RoR), Ruby
  • App Developer

    2018 - 2018
    We Are Alexander
    • Implemented database storage for long value persistence.
    • Debugged the Salesforce authentication process.
    Technologies: Salesforce, Angular, iOS, TypeScript, Ionic
  • Full-stack Developer

    2018 - 2018
    • Created an API for third-party integration.
    • Supported the Engine Yard deployment process.
    • Changed the React front-end based on AB testing results.
    • Provided TDD development of back-end functionalities.
    • Generated automated API documentation.
    Technologies: Amazon Web Services (AWS), Engine Yard, Docker, MySQL, AWS, React, Ruby on Rails (RoR)
  • Software Developer

    2018 - 2018
    • Constructed a front-end application using Angular 6, Ngrx, and Nx for multiple Angular applications.
    • Implemented CSS and HTML using the flex-layout system.
    • Integrated the back-end with many external system APIs.
    • Constructed a back-end API for the front-end application to access.
    • Made a Bitbucket Pipeline improvement to run specs on the Rails application.
    Technologies: Angular Flex Layout, NgRx, Bitbucket Pipelines, Angular, RSpec, Docker, Ruby on Rails (RoR)
  • Owner

    2016 - 2017
    Moca Tecnologia
    • Created some Unity games as I delved into the world of startup ownership.
    Technologies: Unity3D, C#
  • Senior Ruby on Rails Developer

    2014 - 2016
    • Integrated a Quickbooks Desktop application with the Procore web app through a web connector that makes SOAP calls to a specified endpoint.
    Technologies: JSON, APIs, SOAP, Ruby on Rails (RoR)
  • Team Leader

    2012 - 2014
    • Created numerous applications using WebRTC technology.
    • Managed outsourced employees based in Vietnam.
    • Started a tech company from zero.
    Technologies: WebRTC
  • Developer

    2011 - 2012
    • Designed and developed systems for for support of the daily activities of the secretary.
    • Implemented various functionalities using the test-driven design methodology with RSPEC.
    Technologies: Capybara, RSpec, CSS, CoffeeScript, Haml, NGINX, Unicorn, Ubuntu, Git, Ruby on Rails (RoR), Ruby
  • Developer

    2009 - 2011
    • Developed a web service using REST for interfacing a web service with a SOA Web Service.
    • Developed several REST services that transcribe calls for SOA, allowing access to the CMNET system for hotel booking.
    • Developed a system for the remittance of scheduled emails and for template registration.
    • Added user control to a system already in production, along with single sign-on functionality for other systems.
    Technologies: Ant, Maven, Hibernate, Spring, JavaScript, JSF, Java


  • Procore Quickbooks Integration

    I created a Ruby on Rails microservice that would receive a call from the QuickBooks desktop software and send it to the main software. The software was created using the Ruby on Rails and the calls were made using the SOAP protocol. Rspec was used as the test framework.

  • One Love

    Creation of the fully responsive website for the version 2 of the website.

  • Qbwc_requests

    An open-source Ruby gem to create Qbwc requests that makes easy for developers to generate Quickbooks requests. It uses RSPEC as the test framework.

  • Física Básica (Basic Physics)

    A mobile application to teach physics, created using Ionic and Angular. The app has 4 years of development and has been used by more than 200,000 users.

    You can also see the iOS version here:

  • Marcações (Ionic)

    This Ionic app connects to a Ruby on Rails back-end to manage the schedule of appointments of the users.

    The app is fully created using the Ionic framework and Angular JS,

  • Paper Hero

    A Unity3D game created by me.

  • Banco de Talentos

    I developed an application for the registration of applicants with interest in lecturing on military policy. Further, I developed a second application for the consultation of the applicant’s information and expertise.

  • Socitrip

    A defunct Ruby on Rails app to manage users' travel recommendations, the app had many functionalities, like Facebook integration.

  • Gamc

    Personal project under active development.

  • Wikimapa

    Wikimapa was an Brazilian startup that was aiming to map slums of Brazil. The web app was made using the Rails framework, with an API to be managed by the mobile app.

  • MIMO

    Mimo was a startup that use to offer photo books that you could create yourself. I created the whole system using Ruby on Rails and many other JS libraries to manage the creation of the photo albums.

  • A Year Building a WebRTC Application: Lessons in Startup Engineering (Publication)
    I've been an Engineer at Toptal for just about one year now, working on the same project since I joined the network: Ondello, a service that connects doctors and patients over WebRTC. When I first joined Ondello, I was hired as a Senior Ruby on Rails Developer, tasked to build a service up from scratch. These days, we're a team of multiple developers working on a fairly large, complex system. With this post, I'd like to share the story behind Ondello. Specifically, I'd like to talk about: how a simple application became not-so-simple, and how our use of cutting-edge technologies posed problems I'd never considered before.


  • Languages

    Ruby, C#, SQL, JavaScript, Java, Unicorn, Haml, CSS, TypeScript, Python, CoffeeScript
  • Frameworks

    Ruby on Rails (RoR), Ionic 3, Unity3D, Ionic, Capybara, PhoneGap, AngularJS, JSF, Spring, Hibernate, Angular, Bootstrap, JavaServer Faces
  • Libraries/APIs

    WebRTC, NgRx, Angular Flex Layout, React, Salesforce API, Facebook API, jQuery
  • Tools

    RSpec, Git, NGINX, Maven, Capistrano, Microsoft Excel, Adobe Fireworks
  • Paradigms

    Test-driven Development (TDD), Agile Software Development
  • Storage

    JSON, PostgreSQL, SQLite, Oracle SQL, MySQL
  • Platforms

    Ubuntu, MacOS, Docker, Engine Yard, iOS, Salesforce, Amazon Web Services (AWS), Unix, Windows, Linux
  • Other

    Ant, SOAP, APIs, Bitbucket Pipelines, AWS, Cordova


  • Graduate Degree in Computer Science
    2004 - 2009
    Universidade Federal Fluminense - Rio de Janeiro - Niteroi


  • SCWCD – Sun Certified Web Component Developer
    Sun Microsystems
  • SCJP - Sun Certified Java Programmer SE 6
    Sun Microsystems

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