From custom software to multi-tenant SaaS in six months

The first version was built for one wholesale distributor: their catalog, their prices, their employees, their payroll. It worked because every business assumption was baked into the code and the data schema.

Within months other wholesalers asked for the same thing. The short path — cloning the project and deploying one instance per customer — solves the first sale and destroys the tenth: every fix has to be applied ten times, every database drifts on its own, and support cost grows linearly with customers.

The real problem was not adding customers. It was no longer having one system per customer.

One deployment, many companies. Every domain entity now hangs off a company identifier, and data access was locked down so no query can run without that filter. Isolation does not depend on a developer remembering to apply it: if the company context is missing, the query fails.

Roles and permissions scoped per company, not globally. A user exists inside a company and their permissions resolve within that scope, because the owner, the salesperson and the warehouse clerk see different parts of the same system.

DIAN electronic invoicing was built once, outside the product. Instead of embedding the regulation into each system, I built a shared service on top of the Factus API that Gran Mayorista, AutomatIQ POS and Mechss all consume. Factus lets a parent company buy a package of electronic documents and distribute it across the businesses using its software, so no small business has to manage its own provider.

The DIAN module is a separate piece from the main system. That was an explicit user request, and it lines up with the technical decision: it keeps regulatory compliance decoupled from the operational core.

More than 10 wholesale businesses run on a single deployment today. A fix ships once and reaches all of them.

Onboarding a new customer stopped being an infrastructure project and became a record in the system.

Commercial expansion is run by my two partners; I keep the platform standing. That split is why growth is not capped by my available hours.

Finish DIAN electronic invoicing via Factus and roll it out across all three products.

The product vision is a network across the associated wholesalers, so businesses already sharing the platform can trade with each other.