It is like this:<p>1. Create full new version<p>2. Run a diff with the old version<p>3. Patch<p>Because of 1, it is bound to be slow (in a computational complexity sense). Based on the popularity of React and its wide acceptance, I wonder if people learn computational complexity theory anymore these days?<p>PS: yes I know there are tricks to make 1 faster, but these are really hacks (require extra thinking and are error-prone) and deviate from the original &quot;React&quot; philosophy (they are basically the old style of doing things), so these don&#x27;t count.