Architecture that survives team turnover
The cost of a senior leaving is not their salary. It is the months of knowledge transfer, the slow re-discovery of design decisions, and the gradual loss of context about why things are the way they are.
Architecture knowledge is a structural asset. In most organisations it lives in people's heads. Not because anyone intends that, but because the tools in use do not treat design decisions as first-class artefacts worth preserving. Wiki pages capture prose. Ticketing systems capture tasks. Neither captures the reasoning that led from a problem to a shape.
The cost of this becomes visible only when someone leaves. A principal engineer resigns, and the payment pipeline they designed three years ago suddenly has no owner who understands why it is structured the way it is. The replacement spends a quarter reconstructing context that could have been read in an afternoon, if it had been written down in a form that survived the person.
Turnover and change are the same problem at different speeds. A team member leaving is a fast transition. A migration is a slow one. If you are looking at how NeoArc handles the slower case, see architecture transitions and roadmaps.
Change is the default state of a working system. NeoArc treats as-is and to-be as two versions of the same model, so the migration plan is a property of the graph, not a slide deck.