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Explain what 'callback hell' is and how to avoid it.

Q: Explain what 'callback hell' is and how to avoid it.

**TL;DR.** **Callback hell** is deeply nested callbacks ("the pyramid of doom") that arises when async steps depend on each other. It's hard to read, error-prone (every level needs its own error check), and tough to refactor. Avoid it with **Promises**, **async/await**, and **named functions** instead of inline nesting. step1(a, (e, r) => { step2(r, (e, r) => { step3(r, (e, r) => { … }) }) }) — error handling repeated at

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A common issue in async programming, understanding its solution is key.

callbacksasynchronouspromisesasync/await

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Pyramid → async/await

// ❌ callback hell
getUser(id, (e, user) => {
  getOrders(user, (e, orders) => {
    getInvoices(orders, (e, invoices) => { /* ... */ });
  });
});

// ✅ flat with async/await
const user = await getUser(id);
const orders = await getOrders(user);
const invoices = await getInvoices(orders);

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