Telecom services Delphi ERP — tax reform without stopping operations

The challenge

A complete ERP (finance, tax, payroll, inventory, sales, point of sale, field operations) in Delphi, distributed across 56 packages and 20 executables, without the original author and without documentation. The Brazilian tax reform required new tax groups on three tax documents issued every day, with a deadline set by law and no stop to invoicing.

The objective

Keep the ERP in production and compliant with tax legislation, without rewriting it and without interrupting document issuance.

The solution

Technical control recovered and documentation produced with AI support reviewed by a human; a shared IBS/CBS calculation module applied to NF-e, national NFS-e and NFC-e, with a homologation mode; idempotent SQL migrations rehearsed on a copy of the database; a deployment package with backup, ordered swap of packages, executable and schemas, README and rollback path; a price-list load tool (spreadsheet to SQL) with simulate, verify and undo scripts. The existing HTTP API service was preserved as the seam for future modules.

The impact

• IBS/CBS adapted on NF-e, national NFS-e and NFC-e inside the Delphi ERP, with no system replacement
• Idempotent database migrations with a homologation mode, rehearsed before every cutover
• Reversible workstation deployments, with a backup and a README in every package
• Price-list load of hundreds of items and thousands of prices per state, with simulate, verify and undo