Most of us don't start our coding journey with React. We usually begin with simpler tools — and one of the most relatable ones is the humble spreadsheet. Surprisingly, spreadsheets offer a powerful mental model for understanding React components, especially when you're learning to manage data and reactivity. In this post, we'll explore what React would look like if you treated every component like a spreadsheet cell.

The spreadsheet analogy

Imagine a spreadsheet: every cell can either contain a value or a formula. Change one cell, and every dependent formula updates automatically. Now think about React components: each one renders UI based on props and state. When those inputs change, React automatically re-renders the component. Sound familiar?

In both cases, you:

• Declare the data (cell value or component props/state)
• Define how it should respond to change (formula or JSX render logic)
• Avoid manual updates — the system handles dependencies

This mental shift helps beginners understand declarative programming and gives experienced developers a new way to reason about component design.

Components as cells

Let's break it down further:

Just like a spreadsheet cell doesn't "know" who's using its value, a component doesn't care which parent is passing it props — it simply reacts to them.

Formula-driven UI: Derived state

Let's look at a simple React example:

function TotalPrice({ quantity, price }) {
  const total = quantity * price;
  return <div>Total: ${total}</div>;
}

This is a formula. total is derived from the inputs. There's no need for useEffect or manual tracking. React's render cycle recalculates the total whenever quantity or price changes — just like a spreadsheet updates dependent cells.

Avoiding unnecessary state and embracing derived computations keeps your UI lean and declarative.

When useEffect becomes an anti-pattern

In spreadsheet terms, useEffect can sometimes feel like saying, "When A1 changes, go manually set B1 to A1 * 2." But if B1 already is defined as =A1*2, you don't need an effect — you need a formula.

This is why misuse of useEffect leads to bugs, stale data, and reactivity that's hard to follow. It's imperative, not reactive.

Instead, let your UI reactivity emerge naturally from render logic and state composition.

Mini spreadsheet in react: A practical example

Let's say we want to build a grid of editable values with a "Total" row that always reflects the sum.

function SpreadsheetRow({ value, onChange }) {
  return (
    <input
      value={value}
      onChange={(e) => onChange(+e.target.value)}
    />
  );
}

function Spreadsheet() {
  const [values, setValues] = useState([10, 20, 30]);
  const total = values.reduce((sum, val) => sum + val, 0);

  function updateValue(index, newVal) {
    const updated = [...values];
    updated[index] = newVal;
    setValues(updated);
  }

  return (
    <div>
      {values.map((val, i) => (
        <SpreadsheetRow
          key={i}
          value={val}
          onChange={(v) => updateValue(i, v)}
        />
      ))}
      <div>Total: {total}</div>
    </div>
  );
}

There's no effect hook. No lifecycle management. It's pure data flow — and it's very spreadsheet.

Replacing useEffect with derived hooks

Here's a more advanced example — you're fetching currency rates and computing converted prices. Normally you might reach for useEffect, but here we use derived computation.

function useCurrencyRate(from, to) {
  const [rate, setRate] = useState(null);

  useEffect(() => {
    fetch(`/api/rate?from=${from}&to=${to}`)
      .then((res) => res.json())
      .then((data) => setRate(data.rate));
  }, [from, to]);

  return rate;
}

function PriceDisplay({ amount, currency }) {
  const rate = useCurrencyRate('USD', currency);
  const converted = rate != null ? amount * rate : '...';
  return <div>{converted}</div>;
}

Now imagine this as a spreadsheet: rate is a fetched cell, converted is just a formula cell. If we used React Server Components or external store hydration, this could be even more reactive without explicit effects.

Dynamic dependencies and conditional cells

What if a spreadsheet cell depended on a different formula based on a condition? We do this in React with conditional rendering and memoized computations:

function Discount({ amount }) {
  const discount = amount > 100 ? amount * 0.1 : 0;
  const final = amount - discount;
  return <div>Final: {final}</div>;
}

This logic is easily extended to selectors, derived atoms (in Jotai), or memoized selectors in Redux Toolkit.

Thinking beyond react: Solid, signals, and the future

Frameworks like Solid.js take this model even further, using fine-grained reactivity where updates only happen at the level of the actual data that changed — not whole components. Instead of re-rendering a row when one cell changes, only the exact cell updates.

React is moving in this direction too — consider useSyncExternalStore, the rise of signals, and server components. All of these embrace a more reactive core, closer to the spreadsheet mental model.

If you understand components as formulas over data, these shifts become less intimidating and more natural.

A fully reactive shopping cart dashboard — Solid.js style

Let's build a simplified Shopping Cart Dashboard, similar to what you'd find in an admin panel or ecommerce front-end.

It includes:

• A global product list with prices and stock levels.
• Cart interactions (add/remove items).
• Derived totals, conditional UI, and fine-grained updates.
• Dynamic styling (stock alerts) — without any re-renders.

Reactive data structure

// store.js
import { signal, computed } from 'solid-js';

// List of available products
export const products = [
  signal({ id: 1, name: 'Keyboard', price: 50, stock: 10 }),
  signal({ id: 2, name: 'Mouse', price: 30, stock: 5 }),
  signal({ id: 3, name: 'Monitor', price: 200, stock: 2 }),
];

// Cart contains product IDs and quantities
export const cart = signal(new Map());

// Add to cart logic
export function addToCart(productId) {
  cart.update((c) => {
    const qty = c.get(productId) || 0;
    return new Map(c).set(productId, qty + 1);
  });
}

This setup allows each product and the cart to be individually reactive.

Product list with stock-level styling

function ProductList() {
  return (
    <ul>
      {products.map((prodSignal) => {
        const prod = prodSignal(); // unwrap signal
        const stockColor = () => (prod.stock < 3 ? 'red' : 'black');

        return (
          <li style={{ color: stockColor() }}>
            {prod.name} - ${prod.price} ({prod.stock} in stock)
            <button onClick={() => addToCart(prod.id)}>Add to Cart</button>
          </li>
        );
      })}
    </ul>
  );
}

Only the stock value's text and color change when stock updates. No re-render.

Cart overview with derived values

function CartOverview() {
  const cartItems = () => {
    const c = cart();
    return Array.from(c.entries()).map(([id, qty]) => {
      const product = products.find((p) => p().id === id)!;
      return { product: product(), qty };
    });
  };

  const total = computed(() =>
    cartItems().reduce((sum, item) => sum + item.product.price * item.qty, 0)
  );

  return (
    <div>
      <h2>Cart</h2>
      <ul>
        {cartItems().map(({ product, qty }) => (
          <li>
            {product.name} x {qty} = ${product.price * qty}
          </li>
        ))}
      </ul>
      <p><strong>Total:</strong> ${total()}</p>
    </div>
  );
}

This leverages reactive mapping and computed for the total.

• Add/remove items → only the necessary <li> or <p> update.
• CartOverview itself never re-renders.

Low stock warning — Conditional UI

function LowStockBanner() {
  const criticalStock = computed(() =>
    products.filter((p) => p().stock < 2).map((p) => p().name)
  );

  return (
    <Show when={criticalStock().length}>
      <div style={{ background: 'orange', padding: '10px' }}>
        Low stock for: {criticalStock().join(', ')}
      </div>
    </Show>
  );
}

Fully reactive — if stock for any item drops below 2, this banner appears immediately.

• No state tracking needed.
• Just a derived computation like in a spreadsheet.

Try this in react — And you'll hit

• useState all over
• useEffect to watch and derive totals
• useMemo or memo to optimize lists
• Re-renders even when values don't change
• Janky animation and scroll if the list grows

In Solid, all of this "just works" reactively at the DOM-node level — no VDOM needed.

Takeaway

The Shopping Cart example shows how signals eliminate the need for re-renders by making the DOM a direct reflection of reactive values — like spreadsheet cells.

This mental model unlocks:

• zero-re-render UIs
• composable reactive logic
• insane performance with large, dynamic data

External data as global cells

External APIs, global state, or context can be thought of as spreadsheet tabs: sources of data that local components (cells) depend on. When that external value changes, any cell that references it should update — and in modern React, tools like useSyncExternalStore or custom hooks let you do exactly that, predictably and with control.

Debugging react like a spreadsheet

Sometimes, understanding a bug becomes easier with this mental model:

• What are the input cells (props/state)?
• What are the computed cells (rendered JSX)?
• Did something introduce a manual update where a formula should go?

This mindset helps you isolate issues caused by shared state, stale values, or unnecessary effects.

Key takeaways

• Components behave like spreadsheet cells: render = formula.
• Avoid storing derived values in state; recompute them.
• Overusing useEffect breaks the reactive flow.
• External stores are like shared data sources across many cells.
• Frameworks like Solid show where React's reactive model could evolve.
• Debug your component tree as if you're tracing spreadsheet dependencies.

Final thought

React was never meant to be imperative. Thinking in terms of spreadsheets reveals what React was always trying to teach us: describe what the UI should be, and trust the system to keep it up to date. The cells will take care of themselves.