John Kropka is a skilled  Ruby on Rails developer with experience contributing to and leading local and remote teams for a variety of corporate clients. Effective upgrading projects from Rails 2.x to 7.x and ruby 1.9 to 3.2. Experience working in both front-end (HTML, CSS HAML, ERB, jQuery)  and back-end (mysql and Postgres databases and asynchronous jobs using delayed job, sidekiq, and resque) technologies.