SmartEngine 2.0: Upgrade Guide
SmartEngine 2.0: Upgrade Guide
Last updated: March 10, 2026 | Applies to: All stores using P: Quantity Breaks & Discounts
Overview
On March 10, 2026, P: Quantity Breaks & Discounts will automatically migrate all stores to SmartEngine 2.0, our next-generation discount engine built on Shopify's latest Functions technology.
This guide covers what SmartEngine 2.0 is, what changes for your store, and what steps you may need to take before the migration date.
What is SmartEngine 2.0?
SmartEngine 2.0 is a high-performance discount engine that runs natively inside Shopify. It replaces the legacy discount method with a faster, more stable system designed to handle complex discount rules at scale.
Key improvements:
- Processes large carts with dozens or hundreds of line items without slowing down checkout
- Stays stable during high-traffic sales events
- Automatically applies the best available deal for each product in real time
What's Changing
1. Discount Stacking
With SmartEngine 2.0, discounts will stack by default. Your product discount rules will automatically combine with:
- Order discounts
- Free gifts
- Free shipping
- Shopify Admin discount codes (including percentage codes)
- Subscription discounts
- Third-party app discounts
Previously, you could opt in or out of combining discount types using the combination settings. With SmartEngine 2.0, all applicable discounts will be applied together automatically.
2. Best Price Logic (Product Discounts)
If a product qualifies for more than one discount rule, SmartEngine 2.0 will automatically apply the one that gives the customer the best price.
Example: If a product has both a variant-level rule and an all-products rule, the system picks whichever gives a higher discount, rather than following a fixed priority order.
Old logic (priority based): Variant > Product > Collection > All Products
New logic: Best price wins
3. Discount Combinations No Longer Configurable by Default
The option to opt out of discount combinations (previously available via combination settings checkboxes) will no longer be supported by default after migration.
Before and After Comparison
Feature | Before SmartEngine 2.0 | After SmartEngine 2.0 |
|---|---|---|
Discount method | Legacy Shopify functions | Latest Shopify Functions |
Large cart handling | May slow down | Handles seamlessly |
Product discount logic | Priority-based (Variant first) | Best price wins |
Discount stacking | Configurable (opt in/out) | On by default |
Combination settings | Manually controlled | Automatic |
What You Need to Do
If you are ready for the upgrade
Your store will be migrated automatically on March 10, 2026. After the migration, take a moment to check your discount behavior and make sure everything works as expected. If anything looks off, our 24/7 Live Chat is always here for you.
If you rely on strict priority or blocking rules
Contact us immediately via 24/7 Live Chat before March 20th. Our team will review your current setup and help you find the best path forward.
If you are not sure how this affects your store
Book a call with our experts. We will audit your current discount rules and walk you through exactly what will change before the migration date.
Updated on: 03/03/2026
Thank you!