The theory has its roots here: 
<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Production_line" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Production_line</a>
<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Division_of_labour" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Division_of_labour</a><p>Whether backend vs frontend is the right &quot;seam&quot; for division of labor depends entirely on the complexity of the systems at play, as opposed to some arbitrary generalization of all backends and frontends as you seem to be making here.