<?php
require __DIR__.'/vendor/autoload.php';
$app = require_once __DIR__.'/bootstrap/app.php';
$kernel = $app->make(Illuminate\Contracts\Console\Kernel::class);
$kernel->bootstrap();

$members = [
    ['tier' => 'E', 'timestamp' => 10], // Passive
    ['tier' => 'C', 'timestamp' => 20], // 1 direct recent
    ['tier' => 'A', 'timestamp' => 30], // 2 directs latest
    ['tier' => 'A', 'timestamp' => 15], // 2 directs older
    ['tier' => 'A', 'timestamp' => 25], // 2 directs mid
    ['tier' => 'C', 'timestamp' => 5], // 1 direct older than E!
];

usort($members, function($a, $b) {
    if ($a['tier'] !== $b['tier']) {
        return $a['tier'] <=> $b['tier']; // A > B > C (Ascending alphabetically)
    }
    return $a['timestamp'] <=> $b['timestamp']; // Older timestamp smaller value wins
});
print_r($members);