- [Stack Overflow - Can a React Redux app scale as well as Backbone?](http://stackoverflow.com/questions/34782249/can-a-react-redux-app-really-scale-as-well-as-say-backbone-even-with-reselect)

While React Redux does work to minimize the number of times that your `mapStateToProps` function is called, it's still a good idea to ensure that your `mapStateToProps` runs quickly and also minimizes the amount of work it does. The common recommended approach is to create memoized "selector" functions using the [Reselect](https://github.com/reactjs/reselect) library. These selectors can be combined and composed together, and selectors later in a pipeline will only run if their inputs have changed. This means you can create selectors that do things like filtering or sorting, and ensure that the real work only happens if needed.

- [#815 - Working with Data Structures](https://github.com/reactjs/redux/issues/815)

- [Reselect #47 - Memoizing Hierarchical Selectors](https://github.com/reactjs/reselect/issues/47)

The `connect` function takes two primary arguments, both optional. The first, `mapStateToProps`, is a function you provide to pull data from the store when it changes, and pass those values as props to your component. The second, `mapDispatchToProps`, is a function you provide to make use of the store's `dispatch` function, usually by creating pre-bound versions of action creators that will automatically dispatch their actions as soon as they are called.

If you do not provide your own `mapDispatchToProps` function when calling `connect`, React Redux will provide a default version, which simply returns the `dispatch` function as a prop. That means that if you _do_ provide your own function, `dispatch` is _not_ automatically provided. If you still want it available as a prop, you need to explicitly return it yourself in your `mapDispatchToProps` implementation.

**Documentation**

- [React Redux API: connect](https://github.com/reactjs/react-redux/blob/master/docs/api.md#connectmapstatetoprops-mapdispatchtoprops-mergeprops-options)

- [React Redux #89 - can i wrap multi actionCreators into one props with name?](https://github.com/reactjs/react-redux/issues/89)

- [React Redux #145 - consider always passing down dispatch regardless of what mapDispatchToProps does](https://github.com/reactjs/react-redux/issues/145)

- [React Redux #255 - this.props.dispatch is undefined if using mapDispatchToProps](https://github.com/reactjs/react-redux/issues/255)

- [Stack Overflow - http://stackoverflow.com/questions/34458261/how-to-get-simple-dispatch-from-this-props-using-connect-w-redux/34458710](How to get simple dispatch from this.props using connect w/ Redux?)

Early Redux documentation advised that you should only have a few connected components, near the top of your component tree. However, time and experience has shown that that generally requires a few components to know too much about the data requirements of all their descendants, and forces them to pass down a confusing number of props.

The current suggested best practice is to categorize your components as "presentational" or "container", and extract a connected container component wherever it makes sense:

- [Twitter - emphasizing "one container" was a mistake](https://twitter.com/dan_abramov/status/668585589609005056)

- [#419 - Recommended usage of connect](https://github.com/reactjs/redux/issues/419)

- [#756 - container vs component?](https://github.com/reactjs/redux/issues/756)

- [#1176 - Redux+React with only stateless components](https://github.com/reactjs/redux/issues/1176)

- [Stack Overflow - can a dumb component use a Redux container?](http://stackoverflow.com/questions/34992247/can-a-dumb-component-use-render-redux-container-component)

The Redux "examples" folder has several sample projects of varying complexity, including a "real-world" example. While many companies are using Redux, most of their applications are proprietary and not available. A large number of Redux-related projects can be found on Github, such as [Sound-Redux](https://github.com/andrewngu/sound-redux).

- [Reddit - Large open source react/redux projects?](https://www.reddit.com/r/reactjs/comments/496db2/large_open_source_reactredux_projects/)

- [HN - Is there any huge web application built using Redux?](https://news.ycombinator.com/item?id=10710240)

Authentication is essential to any real application. When going about authentication you must keep in mind that nothing changes with how you should organize your application and you should implement authentication in the same way you would any other feature. It is straightforward:

1. Create action constants for LoginSuccess, LoginFailure, etc.

2. Create actionCreators that take in a type, credentials, a flag that signifies if authentication is true or false, a token, or errorMessage as a payload.

3. Create an async action creator with redux-thunk middleware or any middleware you see fit to fire a network request to an api that returns a token if the credentials are valid and proceeds to save in local storage or a response to the user if it is a failure which is handled by the appropriate actionCreators that you made in step 2.

4. Create a reducer that can return the next state for each possible authentication case (LoginSuccess, LogoutFailure).