Conversations like this are always difficult to discuss at a high level because the way we implement the words we use can be very different. Code can be written

Conversations like this are always difficult to discuss at a high level because the way we implement the words we use can be very different. Code can be written in a way that a lot of complexity is added in order to make it extensible, or it can be written in a way where simplification is used to make it extensible. Both authors would agree that extensible is good.