Dacris - Pre-Order Validation & Advanced Promotion Engine

About the client

Dacris is one of the leading office supplies distributors in Romania, with a complex ERP infrastructure and a wide portfolio of corporate clients and distributors.

The challenge

In corporate e-commerce, orders are often placed as pre-orders requiring later approval. Unlike classic B2C, promotions cannot simply be frozen at the moment of cart submission, because by the time an order is approved, promotions or product availability may have changed. The system needed to guarantee both flexibility for administrators and predictability for end users.

The solution

I built an Advanced Promotion Engine with Pre-Order Validation Logic:

• Dynamic promotions – supports a wide variety of rules (e.g., “Buy N, get X free”, “Minimum cart value → gift”, “Buy one, get % off second item”).
• Snapshot & validation – each pre-order saves a snapshot of promotions and effects (discounts, gifts). Upon approval, a validation engine checks for:
• Price increases → flagged for review.
• Gifts/discounts no longer available → flagged for review.
• New promotions → ignored unless they affect chosen items.
• Cross-product logic – greedy pairing algorithm ensures optimal discount distribution and full traceability.
• Fairness guarantee – no promotion ever applies silently to the user’s disadvantage.

The results

Handles dozens of overlapping promotions in real-time.

Provides admins freedom to update promotions anytime, while preserving user trust.

Ensures that pre-orders remain consistent, predictable, and transparent, even in a changing commercial context.