# RxJS Learning Path (Pareto Principle)

## 1. Understanding the Basics of Reactive Programming
- [ ] Concept of Streams: Learn what streams are in the context of RxJS.
- [ ] Observables: Understand observables, the core abstraction in RxJS.
- [ ] Observer Pattern: Learn how observers subscribe to observables.

## 2. Core Operations with Observables
- [ ] Creating Observables: Use creation functions like `of`, `from`, `interval`, and `new Observable()`.
- [ ] Subscribing: Understand the `subscribe` method and how to handle data, errors, and completion.
- [ ] Disposing: Learn how to unsubscribe and clean up with the `unsubscribe` method to prevent memory leaks.

## 3. Transforming Data Streams
- [ ] Map and Pluck: Transform the items emitted by an Observable.
- [ ] Filter: Filter data based on conditions.
- [ ] Reduce: Accumulate data over time.

## 4. Combining Streams
- [ ] Merge and Concat: Combine multiple observables into one.
- [ ] SwitchMap: Cancel previous inner observable on a new value.
- [ ] CombineLatest: Combine multiple observables, emitting the latest values of each.

## 5. Controlling the Flow
- [ ] Debounce and Throttle: Control the number of events based on time.
- [ ] Take and First: Limit the number of items from an observable.
- [ ] Skip: Ignore the first n items.

## 6. Error Handling
- [ ] CatchError: Handle errors within the observable chain.
- [ ] Retry: Retry an observable sequence on error.

## 7. Subjects and Multicasted Observables
- [ ] Subject: Understand how a Subject can act as both an Observable and an Observer.
- [ ] BehaviorSubject: Know how to use BehaviorSubject for holding and emitting the latest value.
- [ ] ReplaySubject: Learn how to buffer and replay emissions to new subscribers.

## 8. Utility Operators
- [ ] Tap: Tap into an observable sequence to perform side effects.
- [ ] Delay: Delay the emissions of an observable.

## 9. Advanced Concepts
- [ ] Hot vs Cold Observables: Understand the difference between hot and cold observables.
- [ ] Schedulers: Learn how schedulers control concurrency.

## 10. Best Practices and Common Usage Patterns
- [ ] Resource Management: Learn how to use operators like `using` and `finalize` to manage resources.
- [ ] Higher-Order Observables: Get comfortable with observables that emit other observables and how to flatten them with operators like `concatAll` or `mergeAll`.

## Resources to Follow
- [ ] Official Documentation: Start with the official RxJS docs for the most accurate information.
- [ ] Tutorials: Look for hands-on tutorials that focus on the key concepts listed above.
- [ ] GitHub Repositories: Find and study real-world projects using RxJS.
- [ ] Courses and Videos: Use platforms like Coursera, Udemy, or free YouTube tutorials that emphasize the core 20%.
- [ ] Community: Engage with the community on platforms like Stack Overflow, Reddit, or RxJS Gitter.