Simple backoff using a lookup table (original code https://commaok.xyz/post/simple-backoff/)

backoff.php

<?php
function backoffAttempt(callable $request, int $maxAttempts = 10): void {
    $delays = [1,2,4,8,16,32,60,60,60,60]; // in seconds

    for ($i = 0; $i < $maxAttempts; $i++) {
        $success = $request();
        if ($success) {
            return;
        }

        $delay = $delays[$i];
        $jitterFactor = 0.75 + mt_rand() / mt_getrandmax() * 0.5; // 0.75–1.25
        $sleep = $delay * $jitterFactor;
        usleep((int)($sleep * 1e6));
    }

    throw new RuntimeException("Failed after $maxAttempts attempts");
}

// Example usage:
try {
    backoffAttempt(fn() => makeHttpRequest());
} catch (RuntimeException $e) {
    echo $e->getMessage();
}