The Constant Frozen at Boot Bug: A Ruby Exercise For An Interview

I like interview questions that come from real incidents instead of a puzzle book. You can&rsquo;t google your way out of them, and the candidate&rsquo;s reasoning maps directly onto the job. This one came from a payment service. It looks trivial. It is not. I&rsquo;ve stripped the production code and rebuilt the same shape around a fake payment router. The bug is identical; the names are not. The…