Delphi 7 to Delphi 12 modernisation for a long-running line-of-business system
Brought a 15-year-old Delphi 7 codebase up to Delphi 12 with a new VCL skin, packaged installers and modern database access. No customer-visible downtime.
The brief
An ISV with paying customers on a Delphi 7 product needed to move forward without breaking compatibility. They had been told a full rewrite would take 18 months.
What I built
- Incremental upgrade through Delphi XE -> 10.4 -> 12 with regression testing at each step.
- Modern database access layer (FireDAC) replacing legacy BDE/ADO mix.
- New installer pipeline with code signing and silent-update support.
Outcome
Shipped in five months, not eighteen. Existing customer data files opened unchanged. The vendor now ships monthly releases.