&gt; so long as it works.<p>That&#x27;s what I call the &#x27;happy path fallacy&#x27;. If code performs along the happy path, then great, move fast, break things and release. Never mind that outside the happy path there are tons of issues, bugs, things never even looked at until they suddenly are found to be the root cause of a major breach. Those parts do not get the attention they need because there is no direct economic incentive to do so.<p>Software is not at all done when it &#x27;works&#x27;. It&#x27;s only done when it works well for <i>all</i> input and there are no unknown paths of execution that lead to unexpected results. It&#x27;s pretty rare for a codebase with more than a few 100 lines to be completely known to such a level that there isn&#x27;t a way to cause it to do something the author did not intend to be there. Complexity is a very bad enemy in that respect and code tends to get extremely complex and hard to reason about if you don&#x27;t have iron discipline during the design process.