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Tyler Marshall

Shopify Plus Engineer

The Shopify work isn’t theme work.

It starts where themes stop.

Configurators, Shopify Functions, and checkout extensibility for teams who have hit the platform’s edges.

  • Shopify Plus
  • Product Configurators
  • Shopify Functions
  • Checkout Extensibility
  • Complex PDP Architecture
  • GraphQL & Bulk Ops
View selected work

Cart Transform

Six bundle families, one Cart Transform

Slide 1 of 5: Six bundle families, one Cart Transform

Trusted by

Brands I built for

Selected work

Production storefrontsReal constraints

All case studies

Engineering

Read the code, not the claim

All artifacts
Shopify FunctionTypeScript

Preserving tiered set prices with Cart Transform

A merchant needs configurable greenhouse kits to use prices managed as catalog tiers while preserving each selected module as an order component that carries inventory.

Known limits

Carrier variant
Every price tier needs a real carrier variant; the Function cannot create or select that cart line.
Allocation
Equal component allocation misstates line value when selected items have different economic weights.
Selling plans
Selling plan lines cannot be expanded, so this contract cannot price subscription kits.
Stale IDs
Stale component IDs are detected only when Shopify applies the expansion.
Currency
The money model supports only presentment currencies with two decimal places.
Complex commercePlus platformCatalog architecture
Theme patternLiquid

Dynamic catalog data through Liquid search

A merchant needs a large architectural lighting configurator to request only the selected product data without embedding the complete sibling catalog in the initial page.

Known limits

Data access
The search template can expose only catalog data available to the storefront.
Route caching
Cache behavior for alternate search views still needs a two request check on each deployed theme.
Projection size
Each response returns at most 120 option rows, so larger families need narrower requests.
Variant access
Products whose complete variant arrays are unavailable return an error and need a different data path.
Catalog architectureComplex commerce

Judgment

Where the logic belongs

The requirement sets the boundary. The decision is which layer owns each part, and what that costs.

Read case study

Worked decision

Discount engraving without giving away the case

Requirement
Make eligible engraving free when configured purchases merge engraving into a parent line or expand it into separately represented components.
Shopify boundary
After transformation, engraving may no longer be a standalone line. The discount must recover its eligible value without discounting the entire configured purchase.
Architecture
Cart Transform carries merged engraving value forward. A Discount Function reads that value or an allowed engraving catalog; the theme displays Shopify’s allocations.
Alternative
Making the whole parent free would also give away the case. A fixed discount preserves the distinction between case price and engraving value.
Tradeoff
Expanded bundles depend on an engraving price catalog maintained in code. Product identities, tier rules, and prices must remain synchronized with storefront configuration.
Validation
Unit tests for the engraving discount cover transformed shapes, code-maintained prices, currency handling, and invalid payloads. Incomplete reader contracts return no discount candidate.

Where it can live

  • Theme

    Displays allocations

    Used here

  • Shopify Function

    Carries value and applies discounts

    Used here

  • Checkout UI Extension

    Checkout UI and workflows exposed through Shopify targets, components, and APIs.

  • Admin configuration

    Campaign setup

    Used here

  • App

    Application-owned workflows or state, with deployment, synchronization, and operational responsibilities.

  • External service

    Work outside Shopify runtimes, adding another system boundary and availability dependency.

Delivery

Inside a delivery team

I worked in agency delivery teams. My current workflow uses AI for codebase exploration and implementation, while I remain responsible for decisions, verification, and handoff.

Figma to launch

I turn Figma designs into responsive Shopify sections, working through content variations and merchant editing needs. I check the implementation against the design and clarify behavior the screens leave open.

Inherited themes

I use AI to explore unfamiliar themes and locate the code behind a feature. I check those findings against the source and storefront behavior before deciding where and how to make a change.

Team coordination

In agency projects, I kept PMs informed of blockers, clarified missing product and cart states with designers, and agreed on ownership with other developers before changing shared theme code.

Git and review

I keep pull requests focused, including AI-assisted changes, and explain the purpose, theme preview, checks run, and relevant limits so another developer can assess both the implementation and its storefront behavior.

QA and release

I combine automated checks with storefront testing, including unavailable variants and cart updates. Before release, I confirm readiness and publishing responsibility; afterwards, I verify the changed flow on the live store.

Handoff and debugging

I document setup, merchant settings, and known limits so the next person can continue the work. For reported issues, I gather reproduction details, trace the affected flow, and share findings alongside the proposed fix.

In practice

From Figma to an editable storefront

For GolfN, I recommended Eurus, agreed the foundation with the client, and translated the approved Figma direction into Shopify sections and templates. Products, collections, promotional content, images, and calls to action remained editable by the merchant.

Read about the Figma-to-Shopify build

Taking a change through review and release

On an agency theme update, I shared a preview and test notes with the PM and another developer. We resolved an unavailable product state before approval, agreed who would publish, and checked the purchase flow afterwards. I left configuration notes for the person maintaining it.

Store Lab

Same theme - Tyler Different builds powered by AI

Every demo store is built on Tyler, my custom Shopify theme, using an AI-assisted development workflow. These are for different catalogs and buying journeys.

3 of 6 Stores

Premium audio equipment

Tyler Electronics

Model
DTC
Catalog
Medium, variant-heavy
  • Attribute filtering
  • Variant color swatches
  • Product specification highlights
  • Accessory add-ons
  • Bundle builder with volume discount
  • Back-in-stock notifications
Passwordtyler

tyler-electronics-rjbejwmw.myshopify.com

Beauty & skincare

Tyler Cosmetics

Model
DTC · Multi-brand retail
Catalog
Medium, variant-rich
  • Multi-attribute filtering
  • Variant selectors
  • Build-your-own bundles
  • Personalized skincare quiz
  • Routine-based product discovery
  • Related-product recommendations
Passwordtyler

tyler-cosmetics-6zrjkved.myshopify.com

Organic groceries & food

Tyler Foods

Model
DTC · Multi-brand retail
Catalog
Large, multi-category
  • Predictive product search
  • Build-your-own bundles
  • Tiered bundle discounts
  • Product comparison
  • Variant selectors
  • Shipping estimator
Passwordtyler

tyler-foods.myshopify.com

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