Shopify Plus Development
What Shopify Plus adds for developers — checkout UI extensions, Shopify Functions, B2B, Flow, Launchpad, Markets and expansion stores, and higher API limits — and how each of them is built, so you can tell what you need before you commission it.
- Six years on Shopify
- Checkout extensions and Functions, not checkout.liquid
- Fixed quotes, not hourly guesses
Most Plus pages open with a wall of client logos. This one explains what the plan changes for developers, how those features are built, and where you may not need Plus at all.
Does your project actually need Shopify Plus?
Does your project actually need Shopify Plus?
Plus is a plan, not a development style. What matters is which capabilities your roadmap depends on. Find your situation below, and check Shopify's plan comparison for the current feature list.
| Your situation | What it usually calls for |
|---|---|
| You need custom UI on the information, shipping or payment steps of checkout | Checkout UI extensions on those steps are Shopify Plus only. The Thank you and Order status pages can be extended on every plan. |
| You need custom discount, delivery or payment logic that no public app provides | A custom app that uses Shopify Functions, which needs Plus. Public apps that use Functions work on any plan, so check whether one already does what you want first. |
| You sell wholesale alongside direct-to-consumer on one store | Shopify B2B: companies, locations, catalogues, price lists and payment terms. Check which plan carries the B2B features you need, since the answer has moved over time. |
| You operate several brands or regions that need to be separate | A decision between Shopify Markets on one store and separate expansion stores, which Plus supports. It turns on whether catalogues, themes, staff and data need to stay apart. |
| You run timed launches and need back-office rules to run themselves | Launchpad for scheduling launches and sales, and Shopify Flow for automation. See our Shopify development page for how these fit into a wider build. |
| You sync a large catalogue or order volume with other systems | Plus has higher Admin API limits, which matters for heavy sync. See our ERP integration work for how we design around limits on any plan. |
Six things Shopify Plus adds, and how each is built
This is a description of capability and method. Each piece has its own constraints, and the build is scoped on its own merits rather than sold as a bundle.
Shopify checkout extensibility, in plain terms
Shopify checkout extensibility, in plain terms
Checkout is customised through a fixed set of supported tools rather than by editing its code. Knowing what each tool can and cannot do is the core of scoping any checkout work.
- Checkout UI extensionsAdd or change UI at defined points in checkout using Shopify's components. They cannot access the page's DOM or load arbitrary scripts, which is deliberate: it keeps checkout fast and secure.
- Checkout brandingColours, typography, corner radius and layout settings applied through checkout settings or the Branding API, covering what used to be done with custom CSS in checkout.liquid.
- Shopify FunctionsServer-side rules for discounts, delivery and payment options, and validation. They change what the checkout offers, not how it looks.
- Web pixelsThe sandboxed way to run tracking, replacing script injection. Pixels subscribe to Shopify's standard customer events, which is where analytics and ad platform data should come from.
- Thank you and Order status pagesExtensible on every plan with UI extensions. This is where post-purchase surveys, upsells and order tracking blocks live.
- What replaced checkout.liquid and Scriptscheckout.liquid and the Script Editor are legacy approaches. Their jobs are split across the tools above, and some customisations have no one-to-one replacement. Check Shopify's current documentation for the timeline that applies to your store.
What these Shopify Plus terms actually mean
What these Shopify Plus terms actually mean
Plus has its own vocabulary. This is what the terms mean, so a proposal reads as engineering rather than a feature list.
- Expansion storeAn additional store under the same Plus organisation, typically used for a separate brand, region or channel. It has its own products, theme and settings, which gives isolation at the cost of duplicated upkeep.
- OrganisationThe account layer above individual stores in Plus, where users, permissions and some settings can be managed across stores.
- LaunchpadA Plus tool for scheduling a set of store changes, such as publishing a theme, changing prices or showing a product, to apply at a chosen time.
- Function execution limitsFunctions run under strict limits on size, instructions and runtime. Logic that needs more than this belongs in an app server, with the Function calling pre-computed data from metafields.
- MultipassA Plus feature for single sign-on that lets an external system log customers into Shopify. It is relevant when accounts live elsewhere, though new customer accounts have changed the options.
- Cart and checkout validationA Function that can block checkout with a clear message when a rule is broken, such as a quantity limit or a restricted delivery combination.
Where Shopify Plus builds commonly go wrong
- Scoping checkout work before confirming which extension targets and Function types your plan allows. We start every scope by checking the plan against the roadmap, not the other way round.
- Some old customisations map neatly onto a Function or extension, others are split across several tools, and a few are not possible any more. A discovery audit lists each one and says which category it falls into.
- Every extension adds to checkout weight and to the number of things that can fail at the moment of payment. Fewer, clearer extensions are usually easier to keep fast and to measure, as covered in our Shopify CRO work.
- Several stores that began identical diverge over time as each gets its own fixes. A shared codebase for themes and apps, with per-store configuration, keeps them aligned.
- Logic that works in a small test fails under a large cart or complex ruleset. Functions are designed around the limits and tested with realistic cart sizes.
- If your roadmap does not depend on the capabilities above, a standard plan with the right apps may be enough, and a platform migration is a separate question. We would rather tell you so than scope work around the plan.
If a Plus proposal does not name the plan feature it depends on,
it is pricing a guess. HelloDevs starts by matching the build to the capability, and tells you where a cheaper plan would do.
What a Shopify Plus development project includes
What every HelloDevs Plus quote covers
Every quote covers all of this. If a proposal leaves out any of it, the cost returns later as rework.
- Plan and feature fit checkWhich capabilities the roadmap depends on, which plan features provide them, and where a lower plan would do.
- Scoping documentWhat is built as an extension, a Function, an app or theme code, and why, agreed before any code.
- Checkout extensionsBuilt to Shopify's component and target rules, tested on checkout previews, kept deliberately small.
- Functions with limits in mindWritten and tested against realistic carts, with logic that outgrows a Function moved to an app.
- Tracking via web pixelsEvents delivered through supported customer events, not injected scripts.
- Integration designThrottling, bulk operations and idempotent handlers for any sync with ERP, OMS or other systems.
- Test planCheckout flows tested per market and per payment method before launch.
- Source codeYours, in your repository, from the first commit.
- DocumentationWhat each extension and Function does, how it is configured and how to change it.
How a Shopify Plus development project runs
Five steps, with the plan checked before the build
Nothing is scoped until the plan features it depends on are confirmed, and nothing reaches checkout until it has been tested end to end.
- Fit callYou describe the roadmap. We tell you honestly which parts depend on Plus, which do not, and what we would build for each.
- Fixed quoteA written scope that names the plan feature behind each deliverable, a timeline and a price.
- Build on a development storeExtensions, Functions and theme work built and reviewed in a development environment, never first on your live checkout.
- Test every pathCheckout tested per market, device and payment method, including discount stacking and edge cases in carts.
- Launch and watchStaged rollout where possible, with error and conversion monitoring in the first days after launch.
Shopify Plus development tech stack
Shopify's own extension platform
Included because technical buyers ask, and because a vague answer here usually hides a heavy dependence on third-party apps for work the platform does natively.
The Plus Stack
Shopify CLI projects holding checkout UI extensions in TypeScript and React, Shopify Functions in Rust or JavaScript compiled to WebAssembly, the GraphQL Admin API with bulk operations for sync, Flow for automation, and web pixels for tracking.
- Checkout UI Extensions
- Shopify Functions
- GraphQL Admin API
- TypeScript
- React
- Rust
- Web Pixels
- extensions/checkout-ui/src/Checkout.tsx01
- extensions/discount-function/src/run.ts02
- extensions/web-pixel/src/index.ts03
- shopify.app.toml04
Logic Inside Shopify
Discount, delivery and payment rules run as Functions on Shopify's infrastructure, so they stay fast and available when your own servers are not.
export function run(input) {
return { operations: [] };
}No Checkout Hacks
No injected scripts or DOM patching in checkout. If the supported tools cannot do it, we say so rather than work around it.
checkout-hack.js
No Subcontracting
We do not subcontract. The people on the scope call are the people writing the extensions.
ScopeBuild
Shopify Plus development questions
- It typically depends on which capabilities are involved: a single checkout extension is a much smaller job than a B2B build with ERP-driven pricing across several markets. Other factors are the number of Functions, how many integrations are involved, and how much testing the checkout needs. We quote a fixed price once the scope is clear. The Plus subscription itself is Shopify's pricing, not ours.
- Depends on your roadmap, not only on revenue. The main development reasons are extensions on the information, shipping and payment steps, custom apps that use Functions, and certain multi-store and automation needs. If none of those is on your list, a standard plan is often enough, and we will say so on the scope call.
- It typically depends on how many pieces are involved and how much testing they need. A single extension or Function is quicker than a full B2B or multi-store programme. Checkout work also needs time for testing across markets and payment methods, which we plan in rather than leave to the end.
- Their jobs are split across checkout UI extensions, branding settings, Functions and web pixels, and Shopify publishes the timeline. We start with an audit that lists each customisation and says whether it maps to a supported tool, needs a rethink or can't be reproduced. See maintenance and support for ongoing deprecation tracking.
- Yes, using company accounts, catalogues and price lists, with the plan features you need confirmed against Shopify's current comparison. The design work is usually in keeping prices in step with an ERP, and in making ordering feel right for repeat wholesale buyers.
- Depends on how much has to be separate. One store with Markets is simpler to run when catalogue, staff and theme are shared. Separate stores make sense when brands or regions need independent catalogues, teams or data. We lay out the trade-off against your actual setup before recommending either.
- No, and this page does not describe Plus client work. It explains what the plan adds and how those features are built, from Shopify's public developer documentation and APIs. If you need a Plus Partner for contractual or support reasons, tell us on the first call and we will say plainly whether we are the right fit.
Tell us what your roadmap depends on
Send the capability you need and your current plan. A developer at HelloDevs replies within one business day.
Project examples and buying guides
Review the work, compare your options and prepare a brief before choosing your next step.
- Shopify script tags are being switched off
What breaks, what replaces it, and how to audit a store for it.
- Shopify app development
Where checkout extensions and Functions sit inside a custom or public app.
- Shopify ERP integration
How we design sync around API limits, whatever plan a store is on.
- Headless and web development
The alternative architecture, and when it is worth considering.
Talk to us about Shopify Plus development
Tell us what your roadmap depends on
Send the capability you need and your current plan. A developer at HelloDevs replies within one business day.
