We use it for a few things. We use it internally for a few dashboards because it’s actually really nice to have real-time dashboard data with Firebase. We also use it extensively for live order updating. For example, when a shopper is picking your items, you'll be able to go on your order screen. There will be live showing like found or not found or whatever. You'll have live position updating of your shopper on the map. You will have live information of the status of the order like “Nicole is now picking up your order,” and all these kind of things, so you don’t have to reload the page or pull or anything. Just live updates happen natively through Firebase API, which is nice.

Basically, the trajectory was we had our iOS app, which started out native, right? It started as a native app, and then we realized you have to go through a review process and it’s slow, and at a very early stage, it made sense for us to make it a wrapped web view. Basically, the app would open, and it would be a web view inside of it that we could iterate on quickly and change very rapidly and not have to wait for app store view process to change it. It wasn’t totally a native experience, but it was as actually a pretty good experience and lasted for a very long time and was up until recently the foundation of our current mobile web experience, which is different from our app situation. So for a long time, basically, our app store iOS Instacart app was a wrapped web view of just our store, a condensed version of our store, which meant that we could add things. We could change sales. We could change the formatting. We could change the UI really fast and not have to worry about the app store review process.

This all changed about a year ago, I would like to say, at which point it became a totally native app. We felt comfortable enough with the product and all the features that we made it a native experience and made it a fully featured app.

Before two weeks ago or so, it used to be Backbone views and models, and everything was on our main store app, and our mobile web app, but actually, we just switched our mobile web app to using ReactJS for the interface. So it’s using Backbone models but ReactJS front-end components. Really, it was borne out of the frustration with how the Backbone model-view bindings worked, and it wasn’t especially performant for large views, and we had to do lots of tricks to make it performant. But swapping that out with React views meant that it could be both simpler and faster without having to spend a lot of time on that.

One other interesting thing about that is, since React actually works okay with the Backbone models and the Backbone router and stuff like that, we didn’t have to rewrite the mobile web application and update it to ReactJS. Rewrites are almost always a bad idea. We were able to upgrade pieces of it at a time, move on to React, and now the entire thing is using React and just has the Backbone router and models and stuff like that that we already had, so it's a lot faster.

The main web store is a Backbone.js single page web application, and so it hits API endpoints to do all the calls, and we use those same API endpoints for the consumer iPhone app, the consumer Android app, and the consumer mobile web app. It worked out really nicely, us just building one API and just all these clients, including the web client, using that.

Web has always been in Rails from the beginning, so we used Redis for caching our items, which we had, from the beginning. Rails is kind of what we were comfortable with, and we knew we wanted the front end to be really, really snappy, so we de-normalized all the item attributes into Redis, and that's how it got served out.

So we very, very early on, we were iOS only, then we thought, well we’re missing out on half of the market. We need to add Android. So we had a friend of ours start working on the Android app, and I had to build the API for him, but I was having a really hard time doing that because I didn’t know what he needed exactly, so I built the first version of the web store over the weekend because I wanted to have a client to consume myself for the API I was building.