# Ruby on Rails Trade Tariff App: Makers Academy Talk
> Last Thursday, Matthew gave a talk to the students of Makers Academy about some of the lessons we learned building the Trade Tariff for HMRC & GDS. Makers Academy, a training institution based in London, runs a high-intensity web application development course, where the students…
Author: Matthew Ford
Published: 2013-06-17

<p>Last Thursday, Matthew gave a talk to the students of Makers Academy about some of the lessons we learned building the <a href="https://www.gov.uk/trade-tariff/sections">Trade Tariff</a> for HMRC &amp; GDS. <a href="https://makersacademy.com/">Makers Academy</a>, a training institution based in London, runs a high-intensity web application development course, where the students learn Ruby on Rails, Agile, Lean, and general software development principles.</p><p>After covering the basics of the Trade Tariff apps we developed for HMRC, Matthew described some of the technology that powers it. The main back-end is a Ruby on Rails and Sequel application that powers a JSON API, which is then consumed by the front-end Rails application. He then showed some examples of legacy data we imported and merged into the EU XML data structure.</p><p>One of the biggest challenges of building the UK Trade Tariff was the size and complexity of the data model (see a part of it below).</p><figure class="kg-card kg-image-card"><img src="/images/blog/ruby-on-rails-trade-tariff-app-makers-academy-talk-1.png" class="kg-image" alt="talk" loading="lazy" width="1920" height="1440"  sizes="(min-width: 720px) 720px"></figure><p>The students were keen to understand the development of a real Rails application and took the opportunity to grill Matthew on the challenges they’d face as software developers.</p><p>Given the application is open source, it was a good opportunity for the developers to have a look at a well-tested and complex Ruby on Rails application.</p><p>The Trade Tariff code is open source, so students had an opportunity to look at it. If you are interested, you can also check it out on github:</p><p><a href="https://github.com/alphagov/trade-tariff-backend">https://github.com/alphagov/trade-tariff-backend</a></p><p><a href="https://github.com/alphagov/trade-tariff-frontend">https://github.com/alphagov/trade-tariff-frontend</a></p><p>You can read more about this project in the post below:</p><p><a href="https://gds.blog.gov.uk/2012/08/10/the-all-new-trade-tariff-tool/">The all new Trade Tariff tool</a></p>
