Explain Performance optimization in Laravel with code examples.

// Eager Loading
$users = User::with(["posts", "profile"])->get();

// Query Optimization
$users = User::select(["id", "name", "email"])
    ->where("active", true)
    ->limit(100)
    ->get();

// Database Indexing
Schema::table("users", function (Blueprint $table) {
    $table->index(["email", "active"]);
});

// Query Caching
$users = Cache::remember("active_users", 3600, function () {
    return User::where("active", true)->get();
});

// Route Caching
php artisan route:cache

// Config Caching
php artisan config:cache

// Background Processing
ProcessPayment::dispatch($order)->onQueue("payments");

// Batch Jobs
Bus::batch([
    new ProcessPayment($order1),
    new ProcessPayment($order2),
])->dispatch();