Built-in complete synchrony / consensus

This means building the synchrony into the system without allowing asynchronous behaviour at all. Such systems could be distributed yet still centralized and synchronous, because they will have a single global clock or 'ledger' which establishes the total order on all event within the system.

I would say that most of today's systems are more or less designed this way as a deterministic thinking is deeply ingrained in the thinking of computer scientists and programmers (see A Conversation with Bjarne Stroustrup, Carl Hewitt, and Dave Ungar). And for the good reason - we want to build programs that do something for us, not just do something in-deterministically. Nevertheless, the current socio-techno-economical environment does not allow us to chase for determinism due to many reasons, therefore we have to think how synchrony emerges during operation of the system.