Make no assumptions.

I&rsquo;ve recently been thinking a lot about the concept of &ldquo;soil horizons&rdquo;, which is the idea that there are many distinct layers of soil, from topsoil all the way down to bedrock, which all combine into a soil horizon. Translating this idea into software, the ideal codebase would have a single uniform &ldquo;code layer&rdquo;, but a surprisingly large percentage of production…