Replace Node Chains With a Single Code Node for Complex Logic

When you find yourself building a chain of IF > Switch > Set > IF > Merge nodes to implement branching business logic, stop and consider whether a single Code node would be clearer. The threshold is roughly three or more conditional branches that feed into the same downstream node.

Real-world example: An order processing workflow must classify orders into tiers (standard, priority, VIP), apply different discount rules, flag fraud risks, and set shipping methods -- all before passing to the fulfillment API.

// Mode: Run Once for Each Item
const order = $input.item.json;
const total = order.lineItems.reduce((sum, li) => sum + li.price * li.qty, 0);

// Tier classification
let tier = 'standard';
if (order.customerLifetimeValue > 10000 || order.tags?.includes('vip')) {
  tier = 'vip';
} else if (total > 500 || order.isPriorityMember) {
  tier = 'priority';
}

// Discount rules per tier
const discountMap = { standard: 0, priority: 0.05, vip: 0.10 };
const discount = total * discountMap[tier];

// Fraud flag heuristics
const fraudRisk = (
  total > 2000 &&
  order.isNewCustomer &&
  order.shippingCountry !== order.billingCountry
);

// Shipping method
const shipping = tier === 'vip' ? 'overnight' :
                 tier === 'priority' ? '2day' : 'ground';

return [{
  json: {
    ...order,
    tier,
    subtotal: total,
    discount,
    finalTotal: total - discount,
    fraudRisk,
    shippingMethod: shipping,
  }
}];
```text
One readable Code node replaces what would be 8-12 nodes on the canvas, making the logic auditable and version-controllable.

**Related:** [Use Edit Fields in "Map Each" Mode for Simple Renames](../data-transformation/01-use-edit-fields-in-map-each-mode-for-simple-renames.md) | [Configure Payload Size and Binary Data Mode for Large Files](../performance-and-large-files/01-configure-payload-size-and-binary-data-mode-for-large-files.md)