To deploy a Ruby application, click "Create a service" in the top-left corner in your Dashboard and choose Back-end application.
Connect your Git account and choose the repository to deploy.
Like all back-end applications, a Ruby application must run on a specific cloud server. Choose the location and configuration of this cloud server. You can upgrade it in the future.
Choose your framework in the App customization window.
Click Deploy and you'll see the deployment process in the log. When it's complete, you'll receive a notification. You can also send these notifications to your Slack.
Usually it takes some time to install the cloud server during the first deployment.