Cesar Enrique Diaz, Software Developer in Santa Fe, Santa Fe Province, Argentina
Cesar Enrique Diaz

Software Developer in Santa Fe, Santa Fe Province, Argentina

Member since October 2, 2012
Cesar is a seasoned web developer with extensive experience in Linux, PHP, and Rails. He loves incorporating new technologies into his work to create elegant solutions. He especially enjoys working on high traffic applications such as social network-based sites.
Cesar is now available for hire


  • FoodSpace
    Ruby on Rails, Postgres, JavaScript, jQuery, Heroku, Rspec, Swagger, TDD, Git...
  • New Ventures West
    Ruby on Rails, Postgres, JavaScript, jQuery, Heroku, AWS S3, Git, Bitbucket...
  • Logan
    Ruby on Rails, Postgres, MongoDB, Amazon S3, Heroku



Santa Fe, Santa Fe Province, Argentina



Preferred Environment

Linux (Ubuntu), Sublime, Git

The most amazing...

...software I've coded was an app that worked as a versioning system for cartography maps. The app also copied map files from clients to a main server.


  • Web Developer

    2019 - 2019
    • Fixed bugs.
    • Supported adding new features in the back and front end.
    • Built an API from scratch.
    • Set up Heroku server.
    • Implemented TDD with Rspec plus Swagger for API testing and documentation.
    Technologies: Ruby on Rails, Postgres, JavaScript, jQuery, Heroku, Rspec, Swagger, TDD, Git, GitHub, API, Trello
  • Rails Web Developer

    2018 - 2019
    New Ventures West
    • Fixed pre-existing bugs.
    • Supported the addition of new features.
    • Connected between the app and different third-party APIs like FormStack and WordPress.
    • Set up a staging server environment using Heroku.
    • Worked with AWS S3 files.
    Technologies: Ruby on Rails, Postgres, JavaScript, jQuery, Heroku, AWS S3, Git, Bitbucket, API, Trello
  • Web Developer

    2017 - 2017
    • Developed in Ruby/RoR to maintain relatively new apps. There were four apps for different purposes and some were in version 4 and others in version 5.
    • Built Postgres and MongoDB-based databases.
    • Used Amazon S3 for file storage (mainly images, with some PDFs).
    • Deployed to Heroku servers; I had to configure my local environment to work with it, do database backups, and restore backups from production server to stage server databases, among other things.
    • Built front-end features in CoffeeScript.
    Technologies: Ruby on Rails, Postgres, MongoDB, Amazon S3, Heroku
  • Ruby Web Developer

    2014 - 2015
    • Worked on Ruby on Rails, fixing different applications/bugs.
    • Implemented Twitter Bootstrap.
    • Added Rspec tests to some new features.
    • Worked on jQuery and CoffeeScript code.
    • Worked on an eCommerce Spree app, adding features that helped show it to clients in the front-end information based on stock in stores.
    Technologies: Ruby, Ruby on Rails, Postgres, MySQL, Haml, CoffeeScript, jQuery, CSS, Heroku, Amazon S3
  • Ruby Web Developer

    2014 - 2014
    • Upgraded an existent Sinatra web app.
    • Replaced the external service with internal Ruby tools.
    • Worked on different front-end small changes.
    • Added new test cases for changes or new Ruby code implemented.
    • Added some background Rake tasks.
    Technologies: Ruby, Ruby on Rails, MySQL, Rspec, CoffeeScript
  • Ruby Developer

    2013 - 2014
    Mediyak, LLC
    • Refactored work on main Ruby libraries to order, clean, and fix them.
    • Migrated the app from Ruby on Rails version 2.3.8 to 3.2.17.
    • Migrated the Google Data Calendar version.
    • Migrated the front end to Twitter Bootstrap responsive design.
    • Added new features using Ruby language.
    Technologies: Ruby, Ruby on Rails, Bootstrap, jQuery
  • Software Developer

    2012 - 2012
    • Worked as a freelance developer for a company based in Buenos Aires.
    • Created Whispers, an app to share images taken by smart phones.
    • Developed the back end of the app, in which administrators verify that loaded images are correctly formatted.
    • Wrote the application using Ruby on Rails 3, Riak DB, and jQuery JavaScript libraries.
    • Worked on another app involving using a CouchDB database and improving software that shares messages related to MTV series episodes on Facebook.
    • Built EnglishGetIt and BuenoEntonces, two sites that teach the English and Spanish languages. The apps were created on RefineryCMS using MySQL as an RDBMS.
    • Adapted the original design to incorporate features such as subscription through Facebook and data extraction from CSV files.
    Technologies: Ruby on Rails, Riak, CouchDB, MySQL
  • Software Developer

    2011 - 2011
    Cogwise Solutions
    • Worked as a freelance developer for a company based in Tennessee.
    • Created a web app for online medical records that gives access to physicians, hospital staff, and patients.
    • Allowed users to load their patient records, appointments, and keep track of medical procedures.
    • Wrote the back end using Ruby on Rails 3 and jQuery, and deployed on Heroku servers.
    Technologies: Ruby on Rails, MySQL, jQuery, Git
  • Software Developer

    2009 - 2011
    A 4 Bandas SA
    • Worked as a freelance developer for a company based in Buenos Aires, adding new features to pre-existing projects.
    • Wrote features for projects such as Fotoblog (a social network), Talento Argentino, and Listas (both web applications).
    • Updated Fotoblog from the first version to a second version, adding video sharing tools, functionality allowing users to make friend groups, and a Facebook wall-type feature. The app was developed using Ruby on Rails 2.3, jQuery, and MySQL DB.
    • Added back-end administrator tools to Listas, a platform to share user generated lists of items that also allows users to vote, rank, and share lists. Also worked on the front end to make the design compatible with the new features.
    • Developed using Ruby on Rails 2.3 at first, and then later migrating to Ruby on Rails 3. Also used jQuery MySQL in the second version.
    • Added front-end and back-end tools to Talento Argentino, an application that allows people to follow popular Argentinian TV programs. The tools allowed users to load videos and administrators to approve the videos.
    • Wrote the app in Ruby on Rails 3, using jQuery and MySQL.
    Technologies: Ruby on Rails, MySQL, jQuery, Git
  • Software Developer

    2008 - 2011
    Facultad de Ciencias Económicas
    • Developed intranet apps using Ruby on Rails and coding in PHP.
    • Used PostgreSQL and SQLite as databases.
    • Coded in the Debian GNU/Linux environments.
    • Built an intranet system to control and offer internships at Ciencias Economicas College.
    • Allowed each user student to upload their CV. Teachers could view over four thousand student applications and communicate with prospective interns.
    • Created a web application to organize hardware inventory in a range of locations, including factories, education buildings, and personal corporations. Included functionality to allow the app to keep track of the location and buy/sell history of hardware items as well as to provide reports in XLS files about the hardware in particular sections or offices, including Google Maps references, bills with descriptions of the hardware bought, statistics about the hardware brand bought, and more.
    • Adapted the application to be available in both Spanish and English.
    • Built an intranet system for classroom booking that could also keep track of available classrooms at any given time.
    Technologies: Ruby on Rails, PHP, PostgreSQL
  • Software Developer

    2006 - 2008
    Universidad Nacional del Litoral
    • Worked in web development using PHP and PostgreSQL.
    • Created an internal web application to check the hours worked by teachers for college institutions. The system could check the start and finish times of classes and report the amount of hours worked by a teacher per month in relation to contractual obligations. It also included a messaging system where administrators could communicate with teachers or groups of teachers, giving vital information and news for these people. The reports were made available in XLS and PDF formats for teacher or groups of teachers.
    • Worked to build a web application for the control of a sports campus. Refactored code and implemented view tests for the project using SimpleTest with PHP.
    • Helped develop a web application used to make polls for the institution. Created the statistics module which was used to generate XLS files and graphic reports.
    Technologies: PHP, PostgreSQL
  • Software Developer

    2004 - 2006
    Instituto Provincial de Estadisticas y Censos
    • Developed stand-alone software using Visual Basic 6.0 and Access 97 to format files for cartographic maps.
    • The software was used as a version control of digital maps files. Specifically, it functioned to copy, control, and version files on client machines, employee PCs, and the file hosting server.
    • Created an admin section to control which users were allowed to work on maps and a client machine section to control which PC clients were allowed to manipulate certain files.
    • Developed a separate, small application using PHP and MySQL to make keep track of people working for the institution in 2006.
    Technologies: Visual Basic, Access, PHP
  • Software Developer

    2003 - 2004
    Infosoft Studios
    • Worked on web development of a back-end app for a college social network using PHP and MySQL.
    • Wrote the back end of a website to allow administrators to easily upload content.
    Technologies: PHP, MySQL


  • Rails 5 API with a React/Redux UI (Development)

    Web form where the user (a physician) enters as input patient information and a list of ingredients with associated amounts, and receives as output a PDF with the patient information and ingredients.

  • Whisper (Development)

    An app used to check pictures uploaded to a server from smartphone apps that we also developed. I built the login, the list of images to check, and a user list that admins could manage.


  • Languages

    Ruby, SQL, JavaScript, HTML5, CSS3, SCSS
  • Frameworks

    Sinatra, Ruby on Rails (RoR)
  • Libraries/APIs

    Google API, Facebook API, jQuery, React
  • Tools

    Git, Emacs, Cucumber, Capistrano, GitHub, Spree, Chrome Developer Tools, Gimp, Vim Text Editor, Basecamp
  • Paradigms

    Functional Programming, Agile Software Development, Behavior-driven Development (BDD)
  • Platforms

    Linux, Heroku, Ubuntu, Ubuntu Linux, Debian Linux
  • Storage

    SQLite, PostgreSQL, MySQL, CouchDB, Riak
  • Other

    Spree Commerce


  • Bachelor of Technology degree in Computer Engineering
    1997 - 2003
    Facultad de Ciencias Hidricas - Universidad Nacional del Litoral - Santa Fe, Argentina

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