Thank you for your reply. You are correct that forkJoin() would work in the example presented here. The issue that forkJoin() has is that it only emits after all observables complete, meaning it works great in scenarios where you are waiting on HTTP responses. However, when you have observables that you need to emit immediately or have an observable that will never complete, you need to use different observable patterns. Finally, I presented a better solution, but I left it in the code for the repository. It returns data as soon as the observables emit and doesn’t have the serial issue of the code discussed in the article.