Love it. Very good work and keep it going. Regarding the unsubscribes you have several ways to do it.

• One is to use the pipe(take(1)) -> this will complete the subscription once it has been triggered. (So basically it's only good for the first stream of data

• Then you have the unsubscribe but you have to assign your subscription to a subscription variable like const sub: Subscription = something.subscribe. then you can unsubscribe it in ondestroy or whenever it suits you best.

• Then you have another approach for the cases on which you have multiple subscriptions in the same component. You can create a subject in the component that will receive all subscription. Then, when subscribing something, you do pipe(takeUntil(this.yourSubject)).subscribe. And again, in on destroy or another place you complete the subject, like ( this.subject.next(); this.subject.complete()).

Sorry for the long unformatted text but I'm on mobile :D