Hi team just wondering how we'd do the equivalent in v8? I'm trying to port the react app demo to v8

I can't seem to find in the documentation the equivalent composition or identifying where in the lifecycle certain things are. In this instance what would the equivalent of OnApplicationStarted be?

 public class UmbracoReactStartup : IApplicationEventHandler
{
    public void OnApplicationInitialized(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
    }

    public void OnApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        // Register custom default controller
        DefaultRenderMvcControllerResolver.Current.SetDefaultControllerType(typeof(ReactRoutesController));
    }

    public void OnApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
        // This project uses dependency injection
        // Read more about umbraco and dependency injection here:
        // https://glcheetham.name/2016/05/27/implementing-ioc-in-umbraco-unit-testing-like-a-boss/
        // https://glcheetham.name/2017/01/29/mocking-umbracohelper-using-dependency-injection-the-right-way/


        var umbracoContext = umbracoApplication.Context.GetUmbracoContext();

        var builder = new ContainerBuilder();

        var umbracoHelper = new Umbraco.Web.UmbracoHelper(umbracoContext);

        // Register our controllers from this assembly with Autofac
        builder.RegisterControllers(Assembly.GetExecutingAssembly());
        builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
        // Register controllers from the Umbraco assemblies with Autofac
        builder.RegisterControllers(typeof(UmbracoApplication).Assembly);
        builder.RegisterApiControllers(typeof(UmbracoApplication).Assembly);
        // Register the types we need to resolve with Autofac
        builder.RegisterInstance(ExamineManager.Instance).As<ExamineManager>();
        builder.RegisterInstance(umbracoHelper.ContentQuery).As<ITypedPublishedContentQuery>();

        // Set up MVC to use Autofac as a dependency resolver
        var container = builder.Build();
        System.Web.Mvc.DependencyResolver.SetResolver(new AutofacDependencyResolver(container));

        // And WebAPI
        GlobalConfiguration.Configuration.DependencyResolver = new AutofacWebApiDependencyResolver(container);
    }
}