Which architecture option should we choose?

Questions CTOs ask

How do you weight criteria in an architecture decision matrix?

Weight by how much the criterion would change the decision, not by how important it sounds. Give each criterion a 1 to 5 weight, score each option 1 to 5 against it, and multiply. The discipline is setting weights before you score options — set them afterwards and you will unconsciously tune them until your preferred option wins, which is how a matrix becomes a justification rather than a decision. If two people weight the same criterion very differently, that disagreement is the real conversation and worth having before any scoring.

What is a swing criterion, and why does it matter before you write the ADR?

A swing criterion is one where a small change in score flips the ranking. This tool surfaces both the winning margin and the criterion that decided it, which tells you how robust the decision actually is. A wide margin driven by several criteria is a decision you can defend later; a narrow margin resting on one contested score is a decision you should either revisit or record honestly as a close call. Either way, write the deciding criterion into the Architecture Decision Record — it is the first thing anyone relitigating the decision will ask about.