DaNoize

When users want to show their emotions with the app, the effect has to be immediate. The moment they tap the button on the screen, the sound must be heard in the stadium.

We wanted to make it possible, so we decided to choose a reactive solution. To generate sounds we used mobile devices instead of servers.

What does this mean in practice? A single reaction creates a data stream that is sent to a server. Then it’s aggregated and conveyed to clients’ devices in real-time. Next, in the mobile app, a data stream is directly converted into sound and animations.

This solution reduces a load of a server and a mobile app. It also minimizes data transfer. To achieve our goal, we chose GraphQL technology with Apollo library. On the application’s side, we used MVVM with LiveData.

With these solutions, it takes less time to transmit the sound, and the system receives the signal much earlier.

We didn’t want to generate sound on the server’s side, so we had to create our own solution that generates it on the application’s side. To make it possible, we used the SoundPool library. We’ve extended it, so we could mix soundtracks designed earlier, based on signals sent by the server.

This lets us significantly reduce a load of a server and network connection. The server only provides the instructions on how to mix the soundtracks – it doesn’t send the full tracks directly.

Together with sound engineers we’ve prepared rules and guidelines that allowed us to create a unique sound generating system. That’s the reason why drums, trumpets, or applause sound so realistic.

Every team can adjust the app to its needs in two ways. First, they can add unique reactions, unavailable in the basic version of the app, such as the team’s own shoutout.

The second option is a change of appearance of the UI. Some elements can take on the colors of the team.

GraphQL, a technology created by Facebook, allowed us to minimize the quantity of consumed data.

It also sped up the development process because the Apollo library generates a significant part of code to communicate with a server. It uses files that can be moved between the iOS and Android systems.

We use Statscore, a database with sport-related information conveyed in real-time.

It’s a popular solution in sports betting apps, and it also proves useful in DaNoize. It allows users to immediately find out what happens in the stadium.