· 11 min read
Phasing Is the Architecture: Lay the Reliability Core at Phase One or Rebuild Four Times
A product that must grow from a seed either lays its reliability core at phase one, or rebuilds at every growth step and re-litigates the same reliability questions four times. The core is deliberately more than phase one needs and exactly what the phases after it require, because some properties can be added later at linear cost and some cannot be added later at all. This gives the filter for what belongs in the core, the mechanical test for whether a phase is additive, and what to do when a phase genuinely changes the core's contract.