Why Every Business Analyst Should Learn Node.js in 2026

// explore.js — run with: node explore.js  (Node 18+ has fetch built in)
const url = "https://jsonplaceholder.typicode.com/users";

const res = await fetch(url);
const users = await res.json();
console.log("Records:", users.length);
console.log("Fields in first record:", Object.keys(users[0]));
console.log(JSON.stringify(users[0], null, 2));
// Save as explore.mjs, or add "type": "module" in package.json,
// so top-level await works.

// missing.mjs — which users lack a website or phone?
const res = await fetch("https://jsonplaceholder.typicode.com/users");
const users = await res.json();
const required = ["email", "phone", "website"];
for (const field of required) {
  const missing = users.filter(u => !u[field]).length;
  console.log(`${field}: ${missing} missing of ${users.length}`);
}

// mock-api.mjs — npm install express, then: node mock-api.mjs
import express from "express";

const app = express();
const orders = [
  { id: 101, status: "PLACED", total: 1240.5, eta: "2026-11-10" },
  { id: 102, status: "SHIPPED", total: 560.0, eta: "2026-11-08" },
];

app.get("/api/orders/:id", (req, res) => {
  const order = orders.find(o => o.id === Number(req.params.id));
  if (!order) return res.status(404).json({ error: "Order not found" });
  res.json(order);
});

app.listen(4000, () => console.log("Mock API on http://localhost:4000"));

GET /api/orders/101
200 OK
{ "id": 101, "status": "PLACED", "total": 1240.5, "eta": "2026-11-10" }

GET /api/orders/999
404 Not Found
{ "error": "Order not found" }
(Agreed in workshop: show "We could not find this order" to the user)

// to-csv.mjs — convert a JSON array file to CSV
import { readFileSync, writeFileSync } from "node:fs";

const rows = JSON.parse(readFileSync("orders.json", "utf8"));
const headers = Object.keys(rows[0]);
const escape = v => `"${String(v ?? "").replace(/"/g, '""')}"`;
const lines = [headers.join(","), ...rows.map(r => headers.map(h => escape(r[h])).join(","))];
writeFileSync("orders.csv", lines.join("\n"));
console.log(`Wrote ${rows.length} rows to orders.csv`);

BA scripting boundary (agree with your tech lead)
OK:  exploring test APIs, converting exports, mock prototypes
ASK: anything touching production systems or real personal data
NO:  shipping scripts as product features
Store scripts in a shared repo so the team can review them.

API field table (from exploration)
Field   | Type    | Example      | Required | Notes
id      | number  | 101          | yes      | unique
status  | string  | PLACED       | yes      | PLACED/SHIPPED/DELIVERED
total   | number  | 1240.5       | yes      | INR, 2 decimals
eta     | date    | 2026-11-10   | no       | missing for pickup orders

User story
As a customer, I want to see my order status and expected delivery date
so that I know when my order will arrive.
Acceptance criteria
- Status shows one of PLACED, SHIPPED, DELIVERED
- ETA shown as "10 Nov 2026"; hidden if not provided
- If the order is not found, show "We could not find this order"
API: GET /api/orders/{id} (see field table)

Node.js setup for BAs
1. Install Node.js LTS from nodejs.org
2. Create a folder, run: npm init -y
3. Use .mjs files for modern import syntax and top-level await
4. Install a package when needed: npm install express
5. Run a script: node script.mjs