BusinessOS: a multi-company ERP for a fresh produce trading group

The group runs several trading companies that buy, store, grade and sell perishable stock. Each company needed its own correct books, while management needed one consolidated view of profit, cash and inventory exposure across the group.

Fresh produce adds its own problems: stock is weighed rather than counted, units change between purchase and sale (crates, boxes, kilograms), and wastage and yield losses have to be tracked or margins are fiction. Transfers between group companies had to post correctly on both sides, and payments needed maker-checker approval.

We started with the data model and the boundaries, not the screens:

• ERPNext as a replaceable system of record. All accounting goes through a port-and-adapter layer, so business rules never depend on ERPNext directly. Automated checks fail the build if ERP code leaks into business logic.
• Company scoping everywhere. Every query is scoped to a company, with a separate consolidated, read-only group view. Automated checks fail the build if scoping is missing.
• Reliable sync. Changes go to ERPNext through an outbox with a single worker, so a slow or failed ERP call never loses a transaction.
• An append-only audit trail and maker-checker approvals for money movements.
• Infrastructure as code for local, dev, staging, client-test and production environments.

The platform covers 22 backend modules across commerce, warehouse and inventory, yield and wastage, cash, finance, cost centres, profitability, intercompany, approvals, reporting and notifications. It also has an assistant that answers questions about the business.