When you're replatforming because the current system can't handle the necessary load, it's pretty easy to see if your effort was successful. Load test, or simply let your current traffic hit it and watch it hum along where you once were serving 10% failures. But if the replatforming is done to help development scaling, how do you know the effort was a success?
I accidentally discovered one answer to this question today. You see, Rent the Runway has been replatforming our systems for almost the last two years. We've moved from a massive, and massively complex Drupal system to a set of Java services fronted by a Ruby thin client. Part of the reason for this was load, although we arguably could've made Drupal handle the load better by modernizing certain aspects of our usage. But a major reason for the replatforming was that we simply weren't able to develop code quickly and cleanly, and the more developers we added the worse this got. We wanted to burn the whole thing to the ground and start fresh.
We didn't do this, of course. We were running a successful business on that old hideous platform. So we started, piece by piece, to hollow out the old Drupal and make it call Java services. Then, with the launch of Our Runway, we began to create our new client layer in Ruby using Sinatra. Soon we moved major pages of our site to be served by Ruby with Java on the backend. Finally, in early July, we moved our entire checkout logic into Java, at which point Drupal is serving only a handful of pages and very little business logic.
So yesterday we had a hackday, our first since the replatforming. We do periodic hackdays although we rarely push the entire team to participate, and yesterday's hackday was one of the rarer full-team hackdays. Twenty-some tech team members and four analytics engineers participated, with demos this morning. I was blown away with what was accomplished. One project by a team of four enabled people to create virtual events based on hashtags and rent items to those events, pulling in data from other social media sources and providing incentives to the attendees to rent by giving them credits or other goodies as more people rented with that hashtag. This touched everything from reservations to checkout. We had several projects done by solo developers that fixed major nasty outstanding issues with our customer service apps, and some very nice data visualizations for both our funnel and our warehouse. All told we had over ten projects that I would like to see in production, whether added to existing features, as new features, or simply in the data dashboard displayed in our office.
Compare this to the last full-team hack day and the differences are striking. That hack day had very few fully functional projects. Many were simulations of what we could do if we could access certain data or actions. Most didn't work, and only a handful were truly something we could productionize. The team didn't work any less hard, nor was it any less smart than it is now. The major difference between that hack day and now is that we've replatformed our system. Now adding new pages to the site is simple and doesn't require full knowledge of all the legacy Drupal. Getting at data and actions is a matter of understanding our service APIs, or possibly writing a new endpoint. Even our analytics data quality is better.
So if you're wondering whether your replatforming has really made a difference in your development velocity, try running a hackday and seeing what comes out. You may be surprised what you learn, and you'll almost certainly be impressed with what your team can accomplish when given creative freedom and a platform that doesn't resist every attempt at creativity.