Big rewrites often fail because they postpone value, underestimate hidden behavior and demand that the market stand still.
Map business seams
Find stable boundaries around customer, order, inventory or policy capabilities. These seams become safe places to separate change.
Protect with observability
Before moving logic, make current behavior visible. Golden journeys, tracing and contract tests turn hidden assumptions into an executable safety net.
Good technology does not ask people to trust magic. It earns trust by making judgment visible.
Move value slice by slice
Modernize complete customer outcomes rather than technical layers. Each release should reduce risk or improve the experience.
Retire intentionally
Migration is incomplete until old paths, duplicated data and operational work are removed. Budget deletion as part of delivery.