How do you structure Redux for a 200+ screen enterprise application?

✅ Explanation in Simple Terms

Think of your app like a big office building with 200+ rooms (screens).

Redux is the central storage room where shared files are kept.

To avoid chaos:

• Each floor = a large feature (Payments, Orders, Users)
• Each room = a screen inside the feature
• Each file cabinet = slice (collection of related state + reducers)
• The main building manager = root store

You NEVER mix files from different floors.
Each floor manages its OWN files.
The building manager (store) just connects all floors.

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🎯 Goal of Good Redux Structure

• Easy to find state related to a feature
• Easy to debug
• Easy to scale (add more screens)
• Shared logic goes into shared slices
• Feature logic stays inside feature folders

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⭐ Recommended Structure for 200+ Screens

/src
 ├── app/
 │    ├── store.js
 │    └── rootReducer.js
 │
 ├── features/
 │    ├── users/
 │    │    ├── api/
 │    │    │   └── usersApi.js     (RTK Query optional)
 │    │    ├── components/
 │    │    │   └── UserTable.jsx
 │    │    ├── pages/
 │    │    │   └── UserListPage.jsx
 │    │    ├── slices/
 │    │    │   └── usersSlice.js
 │    │    └── index.js
 │    │
 │    ├── payments/
 │    │    ├── slices/
 │    │    │    └── paymentSlice.js
 │    │    ├── pages/
 │    │    └── components/
 │    │
 │    ├── orders/
 │    ├── dashboard/
 │    └── ...
 │
 ├── shared/
 │    ├── slices/
 │    │    ├── authSlice.js        (login, roles)
 │    │    ├── uiSlice.js          (global loader, modals)
 │    │    └── appConfigSlice.js   (themes, global config)
 │    ├── hooks/
 │    └── utils/
 │
 ├── components/ (truly generic UI)
 └── index.js

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🧠 Why This Structure Works for Enterprise Apps?

✔ Every feature is isolated

Each feature folder contains everything it needs:

• slice
• pages
• components
• API logic

Makes deleting or moving a feature VERY easy.

✔ Store stays clean

Root store only cares about:

{
   users: usersReducer,
   payments: paymentReducer,
   orders: ordersReducer,
   auth: authReducer,
   ui: uiReducer
}

✔ Shared logic stays in /shared

Only truly global state sits here.

✔ Very easy to scale

When a new feature arrives:

features/newFeature/
   slices/
   pages/
   components/
   api/

No breaking changes.

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🧩 Sample Enterprise Redux Store (Very Clean)

app/store.js

import { configureStore } from '@reduxjs/toolkit';
import rootReducer from './rootReducer';

export const store = configureStore({
  reducer: rootReducer,
});

app/rootReducer.js

import { combineReducers } from '@reduxjs/toolkit';

import usersReducer from '../features/users/slices/usersSlice';
import paymentReducer from '../features/payments/slices/paymentSlice';
import orderReducer from '../features/orders/slices/orderSlice';

import authReducer from '../shared/slices/authSlice';
import uiReducer from '../shared/slices/uiSlice';

export default combineReducers({
  users: usersReducer,
  payments: paymentReducer,
  orders: orderReducer,
  auth: authReducer,
  ui: uiReducer,
});

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🍰 Example Users Slice (Feature-level Slice)

src/features/users/slices/usersSlice.js

import { createSlice } from "@reduxjs/toolkit";

const initialState = {
  list: [],
  loading: false,
};

const usersSlice = createSlice({
  name: "users",
  initialState,
  reducers: {
    setUsers(state, action) {
      state.list = action.payload;
    },
    setLoading(state, action) {
      state.loading = action.payload;
    }
  },
});

export const { setUsers, setLoading } = usersSlice.actions;
export default usersSlice.reducer;

---

📄 Example Feature Organization (Users)

/features/users
 ├── slices/
 │    └── usersSlice.js
 ├── api/
 │    └── usersApi.js  (RTK Query or axios calls)
 ├── pages/
 │    └── UserListPage.jsx
 ├── components/
 │    └── UserTable.jsx
 └── index.js

This makes the feature self-contained, modular, portable.

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🧠 Where should Async API calls go?

Option A: Inside slice using createAsyncThunk

Good for large enterprise apps that need unified loading/error handling.

Option B: RTK Query

Best for auto caching, invalidation, etc.

Option C: Custom hook in feature folder

If business logic is complex.

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📌 Rules for Enterprise Redux

✔ RULE 1: NEVER put everything in one big store

Each feature = 1 slice.

✔ RULE 2: Pages should never call the store directly

Use hooks:

const users = useSelector((state) => state.users.list);
const dispatch = useDispatch();

✔ RULE 3: Keep shared state small

Only:

• auth
• modals
• notifications
• app settings
• global loader

✔ RULE 4: Use createSlice everywhere

Its cleaner, faster, less boilerplate.

✔ RULE 5: Keep features isolated

Feature folders should be independent.

---

If a feature like Users grows big, you absolutely can have multiple slices inside the same feature.

Let me explain it in the simplest, cleanest way.

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✅ Yes, you can have multiple slices inside src/features/users/slices/

Think of the feature like a mini-module.

Example:

src/features/users/
   slices/
      usersListSlice.js
      userDetailsSlice.js
      userPermissionsSlice.js
      userFiltersSlice.js

Each slice manages its own independent part of the Users domain.

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🧠 Why Use Multiple Slices?

Because enterprise apps often have:

• Users list screen
• User detail screen
• User permissions screen
• User role management
• Filters, sorting, pagination
• Local UI state (modal open/close)

Keeping all of this inside one huge usersSlice.js will turn it into a 4000-line monster.

Instead, you create small, focused slices.

---

🎯 Recommended Folder Structure for Multiple Slices

src/features/users/
 ├── slices/
 │    ├── usersListSlice.js
 │    ├── userDetailsSlice.js
 │    ├── userPermissionsSlice.js
 │    └── userFiltersSlice.js
 │
 ├── api/
 ├── pages/
 ├── components/
 └── index.js

---

🧩 Combine All User Slices Into One "users" Reducer

Inside your feature folder, create:

src/features/users/index.js

import { combineReducers } from "@reduxjs/toolkit";

import usersListReducer from "./slices/usersListSlice";
import userDetailsReducer from "./slices/userDetailsSlice";
import userPermissionsReducer from "./slices/userPermissionsSlice";
import userFiltersReducer from "./slices/userFiltersSlice";

export default combineReducers({
  list: usersListReducer,
  details: userDetailsReducer,
  permissions: userPermissionsReducer,
  filters: userFiltersReducer,
});

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🏬 Now Your Root Reducer Uses Only One Key

Even though you have 4 slices, the store still sees them as ONE users domain:

rootReducer.js

import usersReducer from '../features/users';

export default combineReducers({
  users: usersReducer,  
  payments: paymentReducer,
  orders: orderReducer,
  auth: authReducer,
});

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📦 Final Redux State Looks Like This

{
  users: {
    list: { ... },
    details: { ... },
    permissions: { ... },
    filters: { ... }
  },
  payments: { ... },
  orders: { ... },
  auth: { ... }
}

Clean.
Organized.
Enterprise ready.

---

🎁 Example Slice (usersListSlice.js)

import { createSlice } from "@reduxjs/toolkit";

const usersListSlice = createSlice({
  name: "usersList",
  initialState: {
    data: [],
    loading: false,
    error: null
  },
  reducers: {
    setUsers(state, action) {
      state.data = action.payload;
    },
    setLoading(state, action) {
      state.loading = action.payload;
    }
  }
});

export const { setUsers, setLoading } = usersListSlice.actions;
export default usersListSlice.reducer;

Each slice stays small and readable.

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🎯 When Should You Split Slices?

Split when a slice grows beyond 300–400 lines or handles different screens.

Examples:

Slice	Purpose
usersListSlice	list table, pagination, loading
userFiltersSlice	search, filters, sorting
userDetailsSlice	profile page, details API
userPermissionsSlice	roles, permissions matrix

This is perfect for a 200+ screen enterprise app.

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🚀 Summary (Very Simple)

✔ Yes, put multiple slices inside the same feature

✔ Combine them inside features/users/index.js

✔ Root reducer still uses only users:

✔ Clean and scalable

🏆 TL;DR (Easiest Summary)

Redux for 200+ screens should be structured like this:

• app/ = store + root reducer
• features/ = one folder per big feature
• shared/ = global slices like auth/ui
• pages/components/api inside each feature
• each feature has its own slice (usersSlice, ordersSlice, etc.)

This makes the application:

• Easy to scale
• Easy to debug
• Easy to onboard new developers
• Modular and maintainable

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