// ❌ Bad: What does this do?
function proc(d) {
    return d.filter(x => x > 18).map(x => x * 2);
}

// ✅ Good: Self-explanatory
function getDoubledAdultAges(userAges) {
    const adultAges = userAges.filter(age => age >= 18);
    return adultAges.map(age => age * 2);
}

// ✅ Modern lazy loading in 2026
import React, { lazy, Suspense } from 'react';
import { optimizeImages } from '@next/image';

// Lazy load heavy components
const AnalyticsDashboard = lazy(() => import('./AnalyticsDashboard'));
const ChartLibrary = lazy(() => import('heavy-charts'));

// Optimized image loading
const App = () => (
    "Loading..."}>
        <AnalyticsDashboard />
        <img {...optimizeImages({
            src: '/large-image.jpg',
            loading: 'lazy',
            priority: false
        })} />
    
);

# ❌ NEVER DO THIS
const API_KEY = "sk_live_1234567890abcdef";
const DB_PASSWORD = "password123";

# ✅ Best Practice 2026
# .env file (gitignored)
API_KEY=${SECRETS:API_KEY}
DB_PASSWORD=${SECRETS:DB_PASSWORD}

# ✅ Using AWS Secrets Manager
import { SecretsManager } from '@aws-sdk/client-secrets-manager';

async function getDatabaseCredentials() {
    const client = new SecretsManager();
    const secret = await client.getSecretValue({
        SecretId: 'production/database'
    });
    return JSON.parse(secret.SecretString);
}

# ✅ Infrastructure as Code (Terraform)
resource "aws_secretsmanager_secret" "db_creds" {
    name = "production/database"
    rotation_rules {
        automatically_after_days = 30
    }
}