Why Every Cloud Engineer Should Learn Node.js in 2026

// AWS Lambda (Node.js): log details of each uploaded object
export const handler = async (event) => {
  for (const record of event.Records) {
    const bucket = record.s3.bucket.name;
    const key = decodeURIComponent(record.s3.object.key.replace(/\+/g, " "));
    console.log(`New object: s3://${bucket}/${key} (${record.s3.object.size} bytes)`);
  }
  return { statusCode: 200, body: "processed" };
};

import { EC2Client, DescribeVolumesCommand } from "@aws-sdk/client-ec2";

const ec2 = new EC2Client({ region: "ap-south-1" });

export const handler = async () => {
  const res = await ec2.send(new DescribeVolumesCommand({
    Filters: [{ Name: "status", Values: ["available"] }],  // unattached
  }));
  const ids = (res.Volumes ?? []).map((v) => v.VolumeId);
  console.log("Unattached volumes to review:", ids);
  // Deleting would be a separate, carefully guarded step.
  return { count: ids.length };
};

import { EC2Client, DescribeInstancesCommand } from "@aws-sdk/client-ec2";

const ec2 = new EC2Client({ region: "ap-south-1" });
const res = await ec2.send(new DescribeInstancesCommand({}));

for (const reservation of res.Reservations ?? []) {
  for (const inst of reservation.Instances ?? []) {
    const hasOwner = (inst.Tags ?? []).some((t) => t.Key === "Owner");
    if (!hasOwner) console.log("Missing Owner tag:", inst.InstanceId);
  }
}

// The SDK reads credentials from the environment or an
// IAM role automatically. Do NOT hard-code keys.
// Local:  configure a profile (aws configure) or env vars
// Lambda: attach a least-privilege execution role
// A good role for the script above allows only:
//   ec2:DescribeInstances

import express from "express";

const app = express();

app.get("/healthz", (_req, res) => {
  res.json({ status: "ok", time: new Date().toISOString() });
});

const port = process.env.PORT ?? 3000;
app.listen(port, () => console.log(`health check on :${port}`));

import express from "express";
const app = express();
app.use(express.json());

app.post("/webhook", (req, res) => {
  // Validate a shared secret header before trusting the payload
  if (req.get("X-Signature") !== process.env.WEBHOOK_SECRET) {
    return res.status(401).json({ error: "unauthorized" });
  }
  console.log("Event received:", req.body?.type);
  res.status(202).json({ received: true });   // accept, process async
});

app.listen(process.env.PORT ?? 3000);

Week 1: JavaScript essentials (async/await, modules, JSON)
Week 2: A first Lambda in Node.js; event objects; logging
Week 3: AWS SDK for JavaScript; a tagging-audit script
        with a least-privilege role
Week 4: Small Express service; deploy as a function;
        README and diagram

- S3-triggered function that records upload metadata
- Scheduled function listing untagged or idle resources
- Webhook receiver that validates a signature
- Health-check API behind API Gateway
Each with: least-privilege role, logging, README

- Wrote Node.js Lambda functions and AWS SDK automation
  scripts (resource tagging audit, idle-resource report)
  with least-privilege IAM roles and structured logging