lazy-loading

class PostsController < ApplicationController
  def index
    @posts = Post.includes(:author)
                 .order(created_at: :desc)
                 .page(params[:page])
                 .per(10)

<div class="layout">
  <ul class="product-list">
    <% @products.each do |product| %>
      <li class="product-row">
        <%= link_to product.name,
              product_path(product),

<%# renders a lazy placeholder; real content arrives when scrolled into view %>
<div class="panel-card">
  <h3 class="panel-card__title"><%= title %></h3>

  <%= turbo_frame_tag dom_id(panel, :frame),
        class: "panel-card__body",

class PostsController < ApplicationController
  def index
    @posts = Post.published
                 .order(created_at: :desc)
                 .page(params[:page])
                 .per(20)

<div class="layout" data-controller="sidebar">
  <aside class="sidebar">
    <%= render "shared/sidebar", active: params[:controller] %>
  </aside>

  <main class="content-area">

import { useEffect, useState, useRef } from 'react'

interface UseInViewOptions {
  threshold?: number | number[]
  rootMargin?: string
  triggerOnce?: boolean

import { lazy, Suspense } from 'react'
import { BrowserRouter, Routes, Route } from 'react-router-dom'
import Layout from '@/components/Layout'

// Eager load critical routes
import Home from '@/pages/Home'

Rails.application.routes.draw do
  concern :tabs do
    get :profile, on: :collection
    get :billing, on: :collection
    get :security, on: :collection
  end

import React, { lazy, Suspense, useState, useEffect } from 'react';

// 1. Component lazy loading
const HeavyComponent = lazy(() => import('./HeavyComponent'));
const AdminPanel = lazy(() => import('./AdminPanel'));
const Dashboard = lazy(() => import('./Dashboard'));

<div class="dashboard">
  <header class="dashboard__header">
    <h1>Overview</h1>
    <p class="muted">Real-time metrics update as they load.</p>
  </header>

import { Injectable, signal, computed } from '@angular/core';

export interface CurrentUser {
  id: string;
  email: string;
  roles: string[];