How Node.js Helps You Land a Data Analyst Job Faster

// Node 18+ has global fetch. Run: node pull.js
import { writeFile } from "node:fs/promises";

const res = await fetch("https://jsonplaceholder.typicode.com/users");
if (!res.ok) throw new Error(`HTTP ${res.status}`);
const users = await res.json();

const header = "id,name,email,city\n";
const rows = users
  .map((u) => [u.id, u.name, u.email, u.address.city].join(","))
  .join("\n");

await writeFile("users.csv", header + rows, "utf8");
console.log(`Saved ${users.length} rows to users.csv`);

async function fetchAllPages(baseUrl, perPage = 100) {
  const all = [];
  for (let page = 1; ; page++) {
    const res = await fetch(`${baseUrl}?_page=${page}&_limit=${perPage}`);
    if (!res.ok) throw new Error(`HTTP ${res.status} on page ${page}`);
    const batch = await res.json();
    if (batch.length === 0) break;
    all.push(...batch);
  }
  return all;
}

# Edit with: crontab -e
# Run the pull script every day at 06:00 and log output
0 6 * * * cd /home/analyst/jobs && /usr/bin/node pull.js >> pull.log 2>&1

// package.json
{
  "name": "data-jobs",
  "type": "module",
  "scripts": {
    "pull": "node pull.js",
    "pull:prod": "node pull.js --target=prod"
  }
}
// Run locally with:  npm run pull

// node validate.js sales.csv
import { readFile } from "node:fs/promises";

const file = process.argv[2];
const text = await readFile(file, "utf8");
const [headerLine, ...lines] = text.trim().split("\n");
const header = headerLine.split(",");

const required = ["order_id", "order_date", "amount"];
const missing = required.filter((c) => !header.includes(c));
if (missing.length) {
  console.error("Missing columns:", missing.join(", "));
  process.exit(1);
}

const badAmounts = lines.filter((l) => {
  const value = Number(l.split(",")[header.indexOf("amount")]);
  return Number.isNaN(value) || value < 0;
}).length;

console.log(`Rows: ${lines.length}, invalid amounts: ${badAmounts}`);

What this tool does:
- Checks the file has required columns
- Counts rows with missing or negative amounts
- Exits with code 1 if columns are missing (so a
  scheduler or pipeline can stop on bad input)

Keep tools like this in a Git repo with a short README
so teammates can use them too.

Task                               -> Tool
Query and aggregate warehouse data -> SQL
Build dashboards and reports       -> Power BI / Tableau / Excel
Statistical analysis               -> Python or R
Pull data from an API              -> Node.js (or Python)
Schedule a refresh                 -> cron / scheduler + Node.js
Reformat or validate files         -> small Node.js tool

Project: Automated weekly sales refresh
1. Node.js script pulls orders from a public API
2. Saves a clean CSV and loads it into SQLite
3. Scheduled with cron (show the crontab line)
4. Power BI / Excel reads the data for a dashboard
5. README explains setup, schedule and limitations
Label clearly: automation supports the analysis.

- Automated a weekly data pull from a REST API with a
  small Node.js script, scheduled it with cron and fed
  the output into a Power BI dashboard, removing a
  manual weekly download