Today is exciting: we’ve completed a year-long project to move Groupon’s web traffic from our legacy Ruby on Rails application to Node.js. We’ve been working hard on this transition and have learned a lot along the way. Groupon will be one of the largest production deploys of Node.js worldwide. We’re currently serving ~50,000rpm and our overall response times have dropped dramatically. Over the next few months we’ll be releasing the libraries we used to power our new Node.js platform and we will be blogging stories about this intense transition.

Some history: Groupon started as a monolithic Ruby on Rails app. Over the last year and a half we’ve been transitioning to a service oriented architecture (SOA) for all of our back-end services. We applied the SOA design pattern to our front-end as well. Instead of having one large web application each internal team can own their own application that only serves the pages for which that team is responsible. Shared logic has moved into services and libraries so teams only need to focus on building the features that their teams own. Groupon is doing cutting edge work in mobile, with nearly 50% of our North American transactions completed on a mobile device in June. Our mobile applications use a JSON API, and our web applications now use the same API, allowing us to focus on maintaining a single contract for all of our consumer web data.