Have you used pure PHP in your projects without third-party frameworks?

Yes, I have used pure PHP without relying on third-party frameworks. This approach is useful for understanding the fundamentals of the language and its capabilities without abstractions.

For example, for a simple REST API, you can write request handling in pure PHP using built-in functions and minimal code:

<?php
if ($_SERVER['REQUEST_METHOD'] === 'GET') {
    echo json_encode(['message' => 'Hello, world!']);
} elseif ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $data = json_decode(file_get_contents('php://input'), true);
    // Process data
    echo json_encode(['received' => $data]);
} else {
    http_response_code(405);
    echo 'Method Not Allowed';
}

Such code is easy to understand and debug, but for larger projects, it is usually more convenient to use frameworks that provide structure and additional features.