A rewrite is not a risk strategy
Large rewrites postpone value while the old system continues to change. Begin by naming the business capability that causes the most operational friction.
Characterize before changing
Capture representative inputs and outputs, then add checks around the current behavior. The goal is not to celebrate legacy behavior, but to make change observable.
Move through controlled boundaries
Introduce a stable interface, migrate traffic in measured steps, and keep rollback possible until production evidence is strong.