Review gates
Each stage has a gate, and it has to pass before the next one opens.
The five stages are not a checklist we rush. Each one ends at a gate with clear criteria, and we do not move on until it is met.
This stops half-finished work from piling up downstream, where it costs the most to fix. Problems surface early, on purpose.
The sequence is real. You always know which stage a build is in and what it takes to leave it.