Use Dependency Injection Containers

Implement a Dependency Injection Container (DIC) to manage object creation and lifecycle. DICs help in decoupling components, improving testability, and managing complex dependency graphs in large applications.

use Psr\Container\ContainerInterface;

class UserService
{
    private $db;

    public function __construct(ContainerInterface $container)
    {
        $this->db = $container->get('database');
    }
}