CleanFlow
Thousands of SKUs, wholesale pricing and CAD/USD selling in one storefront
We built a deep mega-menu taxonomy, a wholesale account portal and Canada and US markets, keeping navigation fast across the full catalog.
Functions, checkout, B2B and integrations
Shopify Plus development
Whether you’re launching on Shopify Plus or have outgrown its settings and App Store apps, OUXP builds what they can’t: a custom storefront, your own discount, shipping and payment rules – including logic lost when Shopify Scripts stopped running on June 30, 2026 – checkout fields and checks, wholesale, selling in more countries, and ERP or CRM integrations. Senior engineers scope the work for a fixed quote, build away from your live store and hand over documented code you own.
Where Shopify Plus stores outgrow settings and apps
Most Plus stores start on configuration and App Store apps. These are the six problems we see most often – and what we build for each.
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Promotions the discount settings can’t express
- What you see
- Tiered, bundle or customer-specific offers need a stack of apps or manual codes – and some can’t be set up at all.
- What we build
- Your rules as Shopify Functions that run inside Shopify’s checkout, tested against the order combinations you actually sell.
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Checkout doesn’t collect or check what you need
- What you see
- PO numbers, delivery dates, gift notes or address rules get sorted out by email after the order.
- What we build
- Checkout UI extensions for the fields and content, and validation that stops orders breaking your rules before payment.
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Wholesale runs outside the store
- What you see
- Trade buyers order by email or spreadsheet, or through a second store with its own catalog to keep in sync.
- What we build
- Shopify B2B: company accounts, catalogs with their own prices, payment terms and a fast reorder path for buyers.
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Every new country adds manual work
- What you see
- Prices, currencies, languages and catalogs are managed region by region – or a new region means another store to run.
- What we build
- Shopify Markets on one store where it fits, and expansion stores where a region needs its own catalog, stock or apps.
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Systems don’t share data
- What you see
- Orders, stock and customer records are retyped between Shopify and your ERP, CRM, PIM, OMS, WMS or 3PL.
- What we build
- Integrations through Shopify’s APIs, webhooks or middleware, with retries, failure alerts and a named owner for every exception.
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Years of quick fixes slow every release
- What you see
- Code from several agencies, overlapping apps and undocumented scripts – nobody knows what a change will break.
- What we build
- An inventory of what runs where, a plan for what to remove, refactor or rebuild, and documentation your team can work from.
Also in scope
- Custom storefronts designed around your brand, customers and business goals – for a new Plus store, a redesign, or new sections when an off-the-shelf theme doesn’t fit the way you sell
- A speed budget on every build, so new features don’t slow the store – or a dedicated performance optimization project when it is already slow
- Metafields and metaobjects for structured product data: spec sheets, size guides, ingredient panels
- Moves to Shopify Plus from Magento, Adobe Commerce, Salesforce Commerce Cloud, BigCommerce and WooCommerce – see Shopify Plus migration paths
Has your store caught up with Shopify’s recent changes?
Shopify retired the two tools most Plus customizations used to run on, and raised the variant limit. If promotions or shipping rules quietly stopped working at the end of June 2026, the first card explains why.
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01
Shopify Scripts stopped running
- When
- June 30, 2026 – no edits after April 15, 2026
Discount, shipping and payment logic that lived in Scripts no longer applies at checkout. It has to be rebuilt as Shopify Functions.
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02
checkout.liquid is retired
- When
- In stages, 2024–2026
The information, shipping and payment steps went first, in 2024. The legacy Thank you and order status pages, with their additional scripts, followed on August 28, 2025 for Plus and August 26, 2026 for other plans. Fields, content, tracking and branding now go through checkout UI extensions, web pixels and the Checkout Branding API.
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03
Up to 2,048 variants per product
- When
- October 2025 – up from 100
Products split to get around the old 100-variant limit can often be merged back, once the theme and apps are checked for large variant counts. The limit of 3 options per product still applies.
Get a quote to rebuild Scripts or checkout customizations
Shopify platform facts as of October 2026.
What we build on Shopify Plus
Six areas cover most Plus development work. Pick one to see what we build and what to weigh before you commit.
Shopify Functions – your business rules inside Shopify’s checkout
Functions are small programs that Shopify runs at fixed points in cart and checkout: when it calculates discounts, lists delivery options or shows payment methods. They replaced Shopify Scripts, which stopped running on June 30, 2026, and they ship inside an app rather than the theme.
What we build
- Discounts: tiered, bundle, buy-X-get-Y and customer-specific offers
- Delivery rules: hide, rename or reorder shipping options by cart, customer or address
- Payment rules: hide or reorder payment methods – net terms only for approved buyers, for example
- Cart and checkout validation: order minimums, quantity limits, blocked address combinations
- Cart transforms: bundles that sell as one line and ship as their components
- Fulfillment constraints and order routing across several locations
Keep in mind
Functions can’t call outside systems while checkout runs, so the data they need – customer tiers, price breaks, allowed regions – is kept in metafields they read. We keep each function small and testable, and keep all your rules in one custom app, so the next change doesn’t mean another app.
Checkout – collect, check and show what you need before payment
Shopify Plus is the only plan that lets you add custom fields and content to the information, shipping and payment steps; other plans can brand the checkout in the checkout editor and extend the Thank you and order status pages. Since checkout.liquid was retired, this runs on Checkout Extensibility – checkout UI extensions, Shopify Functions, the Checkout Branding API and web pixels – which sits in places Shopify provides and keeps working when Shopify updates the checkout.
What we build
- Custom fields – PO numbers, delivery dates, gift messages, tax IDs – saved to the order
- Content and offers: delivery estimates, trust messages, product offers, loyalty balances
- Branding beyond the checkout editor: typography, colors and section styling through the Checkout Branding API
- Thank you and order status pages: surveys, reorder buttons, tracking and offers
- Analytics and ad tracking through web pixels, in line with the store’s customer privacy settings
- Rebuilds of old checkout.liquid and Scripts customizations
Keep in mind
Extensions can’t run arbitrary scripts or change the checkout outside the places Shopify allows. Most requirements fit; when one doesn’t, we say so before building and suggest the closest version that does.
B2B on Shopify Plus – wholesale in the same store
Since April 2, 2026, Shopify’s core B2B features work on every paid plan. Plus adds what larger wholesale operations need: more than 3 catalogs, catalogs assigned to specific companies or locations, deposits, partial payments and payment requests per fulfillment.
What we build
- Company accounts with buyers, roles and locations, imported from your ERP or old platform
- Catalogs and price lists per company, tier or region, with volume pricing and quantity rules
- Net payment terms, deposits and vaulted cards
- Quotes and draft orders for your sales team
- Trade applications with approval, and prices shown only to signed-in buyers
- B2B-only discount, delivery and payment rules in Shopify Functions
Keep in mind
Approval chains beyond Shopify’s built-in buyer roles need custom logic, scoped up front. Before recommending Plus for wholesale, we check whether standard Shopify’s B2B already covers it.
Markets and expansion stores – selling in more countries
Shopify Markets runs several countries from one store: currencies, languages, domains and per-market prices. When a region needs its own catalog, stock, apps or team, Shopify Plus includes up to 9 expansion stores alongside your main store in the same contract.
What we build
- Market setup: currencies, languages, domains or subfolders, and per-market prices
- Translated and localized content, including product data in metafields
- Market-specific catalogs, payment methods and shipping rules
- Expansion stores for regions, wholesale or VIP channels
- Product, price and content sync between expansion stores
- Per-market SEO checks: hreflang, redirects and duplicate content
Keep in mind
Expansion stores don’t share products, stock or settings with the main store, and each needs its own app subscriptions and theme license. One store with Markets is simpler to run, so we start there and add stores only where a region needs its own operation.
Custom apps and Shopify Flow – automation for the manual work
Shopify Flow, Shopify’s own automation app, handles rules such as tagging orders, alerting the team about low stock or holding risky orders for review. When a workflow needs its own data, screens or logic, we build a custom app installed only on your store.
What we build
- Flow workflows for order tagging, fraud review, stock alerts and customer segments
- Flow triggers and actions from your own custom app – a Shopify Plus feature
- Custom apps with admin pages for internal processes: returns approval, bundle setup, production requests
- Scheduled sales, product drops and theme switches with Launchpad, Shopify’s Plus-only scheduling app
- Bulk catalog and price updates through the Admin API
Agreed up front
A custom app is code you keep maintaining. You own the code and the data – that is settled in writing before we build, together with where the app is hosted, who supports and updates it, and what it costs to run each month. More on app and automation development.
Integrations – Shopify Plus connected to the rest of the business
Plus gives integrations 5–10 times the API capacity of other plans – 1,000 points per second on the GraphQL Admin API, against 100 on Basic and Grow and 200 on Advanced – which matters when an ERP syncs a large catalog or high order volumes. Before building, we agree with you where each record originates, how and how often updates move, what happens when a connection fails and who resolves exceptions.
| System | Examples |
|---|---|
| ERP | SAP, Oracle NetSuite, Microsoft Dynamics, Acumatica |
| CRM | Salesforce, HubSpot |
| Marketing | Klaviyo, Attentive, Iterable |
| Search | Algolia, Bloomreach |
| Payments | Adyen, Authorize.net |
| Shipping and fulfillment | ShipStation, EasyPost, Flexport and 3PL providers |
| Subscriptions | Recharge, Skio |
A ready-made connector is never assumed: each integration is scoped after we review the other system’s API and access. Middleware such as Celigo or Boomi fits some stacks, a custom app fits others. More on commerce integrations.
AI in Shopify Plus builds
We help brands adopt practical AI that improves operations and the customer experience – scoped to the work it removes, with Shopify’s own features checked first.
- Customer experience: AI search, product recommendations, shopping assistants and customer support
- Operations: workflow automation, inventory intelligence, product categorization, merchandising automation and content generation
- Delivery: AI-assisted engineering, automated testing, documentation and code-quality checks for faster delivery – every AI-assisted change reviewed by a senior engineer
The stack we build with
- Shopify Functions
- Checkout UI extensions
- Liquid and Online Store 2.0
- Metafields
- Metaobjects
- Shopify Flow
- Shopify Markets
- GraphQL Admin API
- Storefront API
- REST API
- Webhooks
- React
- Next.js
- Hydrogen
- Node.js
- TypeScript
- Cloudflare
- AWS
Do you need Shopify Plus for this?
Not always. Core B2B has worked on every paid plan since April 2, 2026, and App Store apps bring Shopify Functions to every plan – we would rather tell you that than sell you the upgrade. As of October 2026, Plus costs from $2,300/month on a three-year term or $2,500/month on a one-year term, and very high-volume stores move to a revenue-based fee.
| What you need | Basic, Grow and Advanced | Shopify Plus |
|---|---|---|
| Custom fields and content in the information, shipping and payment steps | Not available Branding in the checkout editor only | Included Checkout UI extensions and the Checkout Branding API |
| Thank you and order status page extensions | Included | Included |
| Discount, delivery and payment rules in Shopify Functions | Via public apps App Store apps that use Functions | Included Your own custom app with your rules |
| B2B | Core features Company accounts, up to 3 catalogs, volume pricing, net terms, quotes | Full Adds more than 3 catalogs, company-specific catalogs, deposits and partial payments |
| Selling in several countries | Shopify Markets | Markets and expansion stores Up to 9 more stores in the contract |
| Shopify Flow | Included | Included Plus triggers and actions from your own custom apps |
| How much data integrations can move (GraphQL Admin API limit) | 100 points per second on Basic and Grow, 200 on Advanced | 1,000 points per second |
Shopify plans and features as of October 2026. Shopify changes plan features often, so we confirm the current list before recommending a plan.
Standard Shopify is enough if…
- Your checkout needs branding and post-purchase content, not custom fields or content in the steps before payment
- An App Store app already covers your discount and shipping logic
- Your wholesale fits 3 catalogs or fewer, without company-specific catalogs or deposits
- You sell in a handful of markets from one store
Shopify Plus is worth it if…
- Checkout must collect or show something custom in the steps before payment
- Your promotions need rules no public app handles – often the ones Scripts used to run
- Wholesale needs company-specific catalogs, deposits or partial payments
- Regions need their own stores, or integrations hit the standard API limits
Which way to build – and how it’s priced
There is more than one way to build on Shopify Plus – a new storefront, or Plus features added to the store you have – and the options differ in cost and in how much code you have to maintain afterwards. Every project gets a fixed price after we’ve read your store and code – no open-ended hourly billing.
| Approach | Fits when | Keep in mind | Price |
|---|---|---|---|
| Add Plus features to the store you have | The storefront works; you need discount logic, checkout rules, B2B or another market | Functions and checkout extensions live in an app, not the theme – no redesign needed | Fixed quote per feature, or retainer hours |
| Rebuild Scripts and checkout.liquid customizations | Promotions, shipping or payment rules stopped working on June 30, 2026, or checkout changes were lost when checkout.liquid was retired | Each rule is mapped to a Function before we quote; logic without a direct equivalent is flagged up front | Fixed quote once the rules are mapped |
| Custom app or integration | A workflow or system connection that no maintained app handles | Code you keep running: hosting, support and running costs are agreed before the build | Scoped as a project |
| Theme changes alongside Plus work | The theme is sound and the changes are contained | The store keeps the theme’s structure, limits and update path | From $500; most single customizations $1,000–$5,000 |
| New or fully custom storefront | You’re launching on Shopify Plus, or the current theme can’t be extended to fit how you sell | A custom theme is more code to own – we document it and build sections your team edits in the theme editor | Scoped as a project |
| Headless storefront | You need a fully custom frontend, or one Shopify backend behind several channels | A separate frontend codebase and hosting to run – recommended only when a theme can’t do the job | Scoped as a project |
Theme rebuilds and redesigns are compared on Shopify theme customization, and headless builds on headless commerce.
Honest note
Custom is not automatically better. For every requirement we check three options in order: what Shopify does natively, a maintained app at a known cost, and only then custom code – because custom code is something you keep paying to maintain. If a maintained app does the job for less than a build and its upkeep, we recommend the app.
Before you budget
- What moves the price most: the number of rules and edge cases, integrations, design scope and how much existing code has to be untangled.
- Not in the price: the Shopify Plus subscription and app subscriptions, billed by Shopify and each app’s vendor.
- Not sure where to start? A store audit – $2,500 flat, written report in 5 business days – ranks what to fix first.
- Ongoing work runs on a monthly retainer from $2,500 (20 hours), month-to-month with 30 days’ notice.
How a Shopify Plus project runs
Seven steps, each ending with something you can review before the next one starts. The fixed quote arrives in writing at step 3, before any engineering starts, and nothing reaches your live store until you approve it.
- 1
Discovery
We read the store, code, apps and integrations, and ask what has already been tried. Access goes through a Shopify collaborator request – no shared passwords.
- 2
Solution architecture
We decide what runs natively, in an app, in Shopify Functions or in custom code – and what data each part needs.
- 3
UX and technical planning
Customer journeys, content needs, integrations and a speed budget, mapped on the pages that matter.
- 4
Engineering
Senior engineers build in a staging store or preview theme, using AI tools where they save time. A senior engineer reviews every change.
- 5
Testing
Key journeys on the devices and browsers we agreed, plus checkout, apps, integrations, accessibility, SEO and speed.
- 6
Launch
A planned release with a rollback path, timed away from your peak trading hours, then a close watch on orders and errors.
- 7
Handover and next steps
Documentation and editing guidance for your team, then ongoing improvements through a monthly retainer if you want them.
B2B and multi-market builds, and what clients say
Two builds with the wholesale and multi-market work described above, and what store owners wrote on the Shopify Partner Directory – quoted word for word. Some reviews use our full name, Outstanding Experience.
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Wall Snobs
A trade-only channel with gated pricing, sample orders and custom requests
We built trade applications with approval, logged-in-only pricing, a sample order flow and a custom-request pipeline straight to the print studio.
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“We are large shopify plus store and Sean managed to deliver our most complicated tasks.”
ADDICTvia Shopify Partner Directory (external site)Shopify Plus -
“…We have had some complex needs on our site, where other developers have said it could not be done. ‘Outstanding Experience’ has been able to get it done every time.”
Wall Snobs wallsnobs.com (external site) via Shopify Partner Directory (external site) Store build -
“Others told us it wasn't possible but Vitali created a central inventory system that works with our custom setup. Great work and communication.”
Dive Bar Shirt Clubvia Shopify Partner Directory (external site)Apps & integrations
Reviews sometimes name our engineers – everyone named is part of the OUXP team.
Industries we build Plus stores for
Each industry’s store breaks in its own places – size runs, subscriptions, spec-heavy catalogs, trade pricing. Pick yours to see what we usually build for it.
Emergency support
Store down? Checkout broken?
- Store down or showing errors
- Checkout or payment failures
- A theme or app update broke something
- ERP, inventory or fulfillment sync stopped
Commerce engineers, not a help desk. Every request gets a first response within 30–60 minutes during business hours. Retainer clients with the 24/7 emergency add-on are covered around the clock. Not a client yet? Call anyway.
+1 (818) 651-3226 Emergency line 24/7 · Business hours Mon–Fri, 9 AM–9 PM ET
Shopify Plus development questions
Something else? Ask an engineer – first response within 30–60 minutes during business hours (Mon–Fri, 9 AM–9 PM ET).
How much does Shopify Plus development cost?
Plus work ranges from a single discount rule to a full B2B rollout, so every project gets a fixed quote in writing after we’ve read your store and code. The price moves most with the number of rules and edge cases, the integrations involved and how much existing code has to be untangled. Ongoing development on a retainer costs $2,500–$9,500 a month, and a $2,500 store audit sets the scope when it’s unclear. The Shopify Plus subscription is separate – from $2,300/month on a three-year term, as of October 2026.
When is standard Shopify enough instead of Shopify Plus?
More often than it used to be. Since April 2, 2026, core B2B works on every paid plan, and public App Store apps can bring Shopify Functions to any plan. Plus earns its cost when you need custom fields or content in the checkout steps before payment, your own Functions in a custom app, more than 3 B2B catalogs or deposits, expansion stores or higher API limits. If your requirements don’t need it, we tell you.
Can you build a completely custom Shopify Plus store?
Yes. We design and build fully custom Shopify Plus storefronts – a custom Online Store 2.0 theme around your brand, customers and processes, or a headless build on Hydrogen or Next.js when a theme can’t do the job – with the checkout logic, B2B setup and integrations behind it. New builds are scoped as a project with a fixed price and milestones. Sections come with settings your team edits in the theme editor, values such as discount tiers live in metafields or app settings, and the handover lists which changes still need a developer. The code is yours.
Our store relied on Shopify Scripts – what happens now?
Scripts stopped running on June 30, 2026, so discount, shipping and payment logic that lived in them no longer applies at checkout. We rebuild it as Shopify Functions: line item Scripts mostly become discount functions (some become cart transforms or validation), shipping Scripts become delivery customizations or shipping discounts, and payment Scripts become payment customizations – usually all in one custom app. Logic without a direct equivalent is flagged before we quote, and every rule is tested before it goes live.
Can you take over a Shopify Plus store another agency built?
Yes. We start by reading the theme, custom apps, Functions and integrations, document what runs where, and recommend what to keep, refactor or remove. Access goes through a Shopify collaborator request, never shared passwords. When the state of the store is unclear, a store audit comes first: $2,500 flat, with a written report in 5 business days that you can share with any developer.
Can Shopify Plus integrate with our ERP or CRM?
Yes. We connect Shopify Plus to ERPs such as SAP, Oracle NetSuite, Microsoft Dynamics and Acumatica, and to CRMs such as Salesforce and HubSpot – through the Admin API and webhooks, middleware such as Celigo or Boomi, or a custom app. The same approach covers PIM, OMS, WMS, payment, shipping and marketing systems. Before building, we agree where each record originates, how often updates move, what happens when a connection fails and who resolves exceptions.
Do you build headless Shopify Plus storefronts?
Yes – on Hydrogen or Next.js with Shopify’s Storefront API, for brands that need a fully custom frontend or one Shopify backend behind a website, an app and other channels. Headless doesn’t require Plus – Plus matters for the checkout, B2B and expansion stores around it. We recommend headless only when a theme can’t do the job, because it adds a separate codebase and hosting to maintain, and we put that long-term cost in the proposal. See headless commerce.
Do you provide ongoing development after launch?
Yes, through monthly retainers: Essential ($2,500/month, 20 hours), Growth ($5,000/month, 45 hours) and Dedicated ($9,500/month, 90 hours or a dedicated engineer). Every tier gets a first response within 30–60 minutes during business hours, unused hours roll over one month, and terms are month-to-month with 30 days’ notice. 24/7 emergency cover is included on Dedicated and available as an add-on on Essential and Growth. See retainer and maintenance.
Tell us what your Plus store needs to do next
Whether you’re launching a new Plus store or extending the one you have, talk it through on a strategy call or send the brief. An engineer – not a salesperson – replies within 30–60 minutes during business hours and returns a fixed quote once the scope is clear.