Modernising software without stopping the business

A full rewrite is a full risk

Rewrite-from-scratch projects stall more often than they ship. The safer path is peeling off the parts that hurt most, one at a time.

Draw the boundary from the data

A real module is where data ownership is clear. If two parts write to the same table, they are still one module.

Every stage ships something usable

Each phase should hand over something you can use today — not a progress report.