PHP Platform Engineering Journey

<?php
// No autoloading, no classes, no types
include('config.php');
include('header.php');

$id = intval($_GET['id']);
$result = mysql_query(
    "SELECT * FROM members WHERE id = $id"
);
$row = mysql_fetch_assoc($result);

if ($row['banned']) {
    echo "<h1>BANNED</h1>";
    die();
}
// ... 400 more lines mixed with HTML

class Member
{
    public function __construct(
        private readonly int    $id,
        private string $name,
        private string $email,
        private string $status = 'active',
        private string $role    = 'member',
        private int    $posts  = 0,
    ) {}

    public function toArray(): array { ... }
    public function toJson(): string { ... }
}

class ApiResponse
{
    public static function json(
        mixed $data,
        int $status = 200
    ): void {
        http_response_code($status);
        header('Content-Type: application/json');
        echo json_encode($data);
    }

    public static function success(
        mixed $data,
        string $msg = 'OK'
    ): void {
        self::json([
            'success' => true,
            'message' => $msg,
            'data'    => $data,
        ]);
    }
}

class WebhookEvent
{
    public static function create(
        string $type,
        array  $payload
    ): self {
        return new self(
            id: bin2hex(random_bytes(8)),
            type: $type,
            payload: $payload,
        );
    }

    public function markProcessed(): void
    {
        $this->status      = 'processed';
        $this->processedAt = date('Y-m-d H:i:s');
    }
}

// Step 1: Redirect to authorization server
$authUrl = "https://auth.example.com/authorize?" .
    http_build_query([
        'response_type' => 'code',
        'client_id'     => $clientId,
        'redirect_uri'  => $redirectUri,
        'scope'         => 'member.read member.write',
        'state'         => bin2hex(random_bytes(16)),
    ]);

// Step 4: Exchange code for token (server-side)
$response = http('POST', $tokenUrl, [
    'grant_type'    => 'authorization_code',
    'code'          => $_GET['code'],
    'client_id'     => $clientId,
    'client_secret' => $clientSecret,
]);

-- The slow query: full table scan on 248K rows
EXPLAIN SELECT m.*, COUNT(p.id) AS post_count
FROM members m
LEFT JOIN posts p ON p.author_id = m.id
WHERE m.status = 'active'
GROUP BY m.id;

-- The fix: targeted indexes
CREATE INDEX idx_members_status
    ON members(status);

CREATE INDEX idx_posts_author_created
    ON posts(author_id, created_at);