As someone who has seen several LARGE commercial software projects, there is a definite gradation from &quot;it&#x27;s hard to comprehend these layers of abstraction, but after a few days I kind of understand how they interact&quot; to<p><pre><code>    &#x2F;&#x2F; X - uncommented on 1.2.03 to fix bug
    &#x2F;&#x2F; Y - commented again on 3.2.03 because it broke stuff
    &#x2F;&#x2F; if (condition)
    {
       ... logic here, half of it commented out ...
    }</code></pre>