There’s always a trade off between loading all app code at once giving the user a seamless single page app experience and loading chunks of code on demand. The latter saves a lot of bootstrap time. The initial load time (CRP) gets reduced which means more users can land on your app and you can progressive experience as they use it. The slight delay you are talking about is quite negligible in practice. I haven’t seen any detrimental effects of the same. And for any reason you want to check if a certain module (component) has been loaded or not, you can do that in your component’s componentDidMount lifecycle hook in React or ngOnInit in Angular 2.