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

Verified Expert  in Engineering

Ruby on Rails Developer

Rio de Janeiro - State of Rio de Janeiro, Brazil
Toptal 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.



Preferred Environment

Ubuntu, MacOS

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

Work Experience

Senior Back-end 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, Amazon Web Services (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, 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)


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


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


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 Design, Apache 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.

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.


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


Personal project under active development.


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 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.

Go ActiveInteractation is based on active_interaction and aims to bring the power of the Ruby gem to the Go space.
This library shows my passion for contributing to the open-source community and working with the Go language.

Ruby on Rails Development
As a senior Ruby on Rails developer at Owens Corning, I utilized React for front-end development and Ruby on Rails for back-end solutions. Additionally, I implemented AWS Lambda integrations using Go and handled API integrations with various services.
2004 - 2009

Graduate Degree in Computer Science

Universidade Federal Fluminense - Niteroi, Rio de Janeiro, Brazil


SCWCD – Sun Certified Web Component Developer

Sun Microsystems


SCJP - Sun Certified Java Programmer SE 6

Sun Microsystems


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


RSpec, Git, NGINX, Apache Maven, Capistrano, Microsoft Excel, Adobe Fireworks


Ruby on Rails (RoR), Ionic 3, Unity3D, Ionic, Capybara, PhoneGap, AngularJS, JSF, Spring, Hibernate, Ant Design, Angular, Bootstrap, JavaServer Faces


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


Test-driven Development (TDD), Agile Software Development


JSON, PostgreSQL, SQLite, Oracle SQL, MySQL


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


SOAP, APIs, Bitbucket Pipelines, Cordova, Computer Science

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