Migrating a property agency off a twenty-year-old platform

About 6,500 properties from an undocumented twenty-year-old system. 7,800 raw issues traced to six root causes.

A tester’s odd fee rate proved the file in the new system was an old build, not ours. Then the banking details for owner payments turned out not to exist in the source at all. We named it a blocker and recommended deferring go-live.

Done in a senior enterprise role before Burl, anonymised.