Merchant dashboard
An embedded App Bridge + Polaris UI to create, edit and prioritise bundle rules.
Admin UI
Demo Lab · concept build
Custom Shopify bundle builder app for advanced discount rules
A demo build showing how a private app expresses bundle logic that off-the-shelf apps can't — clean pricing at cart, a merchant UI for the rules, and no extra storefront scripts.
Demo LabThis is a concept / prototype build — illustrative architecture, not a guaranteed result or a named client.
Illustrative architecture
Merchant UI
Rule storage
Shopify Function
Cart discount
Illustrative architecture — concept build, not a client system.
01 — The limit
When off-the-shelf bundle apps get stuck.
Most bundle apps handle ‘buy product A + B for a fixed price’. They struggle the moment the rule has a condition — mixed-eligibility sets, tiered quantities, or ‘cheapest item free’ across a category — and they add storefront scripts and monthly fees on top.
A custom bundle builder expresses the exact rule your merchandising team wants, applies it server-side, and keeps the storefront fast because the discount logic runs inside Shopify rather than as third-party JavaScript.
02 — Worked example
‘Buy 3, cheapest free.’
A rule that trips up generic apps, handled cleanly by a Shopify Function that evaluates the cart and discounts the lowest-priced eligible line.
Shopify FunctionsGraphQL Admin APIApp BridgeTypeScript
- 01Eligibility
- Define which products or collections qualify, and the minimum quantity.
- 02Selection
- The Function finds the cheapest eligible item in the cart at evaluation time.
- 03Discount
- It applies a precise line discount — no coupon codes, no race conditions.
- 04Transparency
- The cart shows the saving clearly so customers trust the price.
03 — Architecture
How the pieces fit.
Rule storage
Rules persisted as metaobjects / records, versioned and readable by the Function.
Metaobjects
Cart Function
A Shopify Function evaluates the cart server-side and returns the discount.
Functions
No storefront bloat
No injected scripts — pricing logic lives inside Shopify, not the theme.
Performance
04 — Custom vs public
A private bundle app vs a listed one.
Typical scope: a focused bundle app sprint. Cautious range — CHF 4,000–10,000+ depending on rule complexity and dashboard needs.
- 01Rule freedom
- Express conditions a settings panel can't — your exact merchandising logic.
- 02Speed
- Server-side discounting keeps the storefront free of third-party scripts.
- 03Cost shape
- A build you own instead of a per-order or tiered monthly fee.
- 04Ownership
- You keep the code and the dashboard; maintenance is optional.
05 — What we would measure
Instrumented from day one.
We don't promise numbers we haven't earned. These are the metrics we'd wire up so the build's value is measured, not assumed.
Average order value — whether bundling actually lifts basket size, and by how much.
Attach rate — how often a bundle is taken versus a single item.
Storefront JS weight & page speed — confirming the build adds no third-party script bloat.
Discount accuracy at checkout — that the rule resolves to the exact price, every time.
Error rate — Function failures or mispriced carts, watched and alerted on.
FAQ
Questions about this build.
No. This is a demo / concept build that shows the architecture and approach. We scope a version tailored to your store from a short audit.
Build something like this.
We'll scope a version tailored to your store from a short audit — architecture, integrations and edge cases included.