Skip to content

Conversion is Powered by Oxify

Conversion
Shopify PlusCheckout ExtensibilityB2B on ShopifyHydrogen

Shopify Plus Development

The Shopify Plus development agency for brands that use the whole platform

Checkout extensibility, Shopify Functions, B2B company accounts, expansion stores, and ERP integration — engineered in version control, documented, and built so the next team can maintain it.

  • Checkout UI Extensions and Shopify Functions, not forked checkout.liquid
  • B2B and DTC from a single Plus instance
  • Integration scoped as discovery, because that is where Plus builds slip
  • Staging, code review, and a deploy path you can reverse
Conversion service illustration in brand blue and green
Explore:Shopify Plus AgencyShopify DevelopmentB2B EcommerceCheckout OptimizationShopify Plus Pricing

What Plus actually changes

Shopify Plus is a different engineering surface, not a bigger plan

Shopify Plus is not a bigger version of Shopify. It is a different engineering surface. The checkout becomes programmable through extensions and server-side Functions, the store can serve B2B buyers and DTC customers from one instance with different pricing and terms, expansion stores turn a single storefront into a portfolio, and API limits rise to the point where real-time integration with an ERP or OMS becomes practical rather than theoretical.

That surface is the reason brands upgrade. It is also the reason Plus builds go wrong more often than standard Shopify builds do. More capability means more places for state to diverge, more systems that must agree with each other, and more code paths that only execute for a subset of customers — which is exactly the kind of code that passes QA and fails in production.

The agencies that do this well are not distinguished by design ability. They are distinguished by process: version control on the theme, a staging environment that mirrors production closely enough to be meaningful, code review on anything touching checkout or pricing, and a deploy path that can be reversed. None of that is glamorous, and none of it appears in a portfolio, but it is what separates a Plus build that can be maintained from one that is quietly rewritten in eighteen months.

We build on Shopify Plus with that bias. We will tell you when a capability you are paying for is not the one that will move your revenue, when headless is the wrong trade, and when the honest answer to a scoping question is that we do not know yet and need to look at your data first.

What we usually find

The problems that bring brands to a Plus development agency

These are the recurring patterns in Plus stores that have grown faster than their engineering process. None of them are unusual, and none of them are unfixable.

Checkout customisations that break on every platform update

Legacy checkout.liquid customisations are a fork of Shopify's checkout, which means every platform change is a potential regression. Checkout extensibility replaces that with versioned, sandboxed extensions and server-side Functions. Brands still on the legacy path should treat migration as scheduled work, not as an emergency response to a breakage.

An app stack that has become the architecture

It is common for a store that grew quickly to be running fifteen to thirty apps, several of which inject scripts into the same page and two of which do roughly the same job. The cost shows up as page weight, as conflicting behaviour that is difficult to reproduce, and as a monthly bill nobody has audited. Consolidation is usually cheaper than it looks and pays back in performance.

Integrations that are technically working and practically unreliable

Inventory that is accurate most of the time, pricing that is correct until a sync fails silently, order data that reconciles except at month end. These are not integration failures in the sense of throwing errors; they are failures of observability. If nobody is alerted when a sync does not run, the integration is not finished.

A theme only one person understands

Plus stores accumulate customisation, and customisation without documentation or version control concentrates knowledge in whoever happened to write it. The risk is not abstract: it surfaces the first time that person is unavailable during a peak trading week. Getting the theme into version control with a real review process is the single highest-leverage change most Plus stores can make.

B2B bolted onto a DTC store

Wholesale customers served through discount codes, manual invoices, and a spreadsheet of agreed prices. It works at low volume and becomes a liability as it grows, because the pricing logic lives in people's heads rather than in the platform. B2B on Shopify moves that into company accounts, catalogs, and price lists that the store itself enforces.

Nobody can say what a release is going to do

Where changes are made directly in the theme editor on the live store, every deploy is an act of faith. Staging environments, branch-based workflows, and a rollback path turn releases from events into routine. This is the least visible thing an agency can improve and frequently the most valuable.

Capabilities

What we build on Shopify Plus

The Plus surface is wide. These are the areas where the platform genuinely does something a lower plan cannot, plus the engineering work that makes any of it maintainable.

Checkout extensibility

Checkout UI Extensions for upsells, trust content, delivery instructions, and custom fields in Shopify's supported checkout slots — versioned and upgrade-safe rather than forked from checkout.liquid.

Shopify Functions

Server-side logic for discounts, shipping method visibility, payment method rules, cart transforms, and bundles. Runs on Shopify's infrastructure, which means it applies consistently rather than depending on a script executing in the browser.

B2B on Shopify

Company accounts, multiple buyers and locations per company, per-company catalogs and price lists, payment terms, and quantity rules — DTC and wholesale from one instance and one product catalog.

Expansion stores

Additional storefronts on the same Plus contract for new regions, brands, or business models, with a deliberate decision about what is shared (catalog, code, content) and what is genuinely local.

Custom app development

Private and custom apps against the Admin and Storefront APIs where an off-the-shelf app does not fit, including the webhook, retry, and alerting behaviour that makes an integration trustworthy rather than merely functional.

ERP, PIM, and OMS integration

Middleware or direct integration with the systems that hold the truth about inventory, pricing, and orders — built with reconciliation and failure alerting rather than assuming the happy path.

Shopify Flow automation

Operational automation for fraud review, tagging, inventory thresholds, B2B approval routing, and internal notifications, so that process lives in the platform rather than in somebody's calendar reminders.

Markets and internationalisation

Multi-currency, multi-language, and market-specific catalog and pricing configuration, with the domain, hreflang, and routing decisions made deliberately rather than inherited from a default.

Theme architecture

A Liquid theme built in version control with sections, blocks, and metafields structured so merchandisers can work without a developer, and developers can change things without fear.

Headless Hydrogen and Oxygen

React-based storefronts on Shopify's own hosting, when the front-end requirement genuinely exceeds what Liquid can do — and an honest conversation about the merchandising and maintenance cost when it does not.

Performance engineering

Core Web Vitals work on the real bottlenecks: third-party scripts, image delivery, render-blocking resources, and app bloat. Measured on field data from real users, not on a lab score from a developer's laptop.

Analytics and data layer

A consistent event schema across GA4, server-side tagging, and ad platform conversions, so that the numbers in three dashboards can be reconciled to each other and decisions rest on something stable.

Not sure whether your roadmap actually needs Plus?

A short call is usually enough to tell whether the capability you are paying for is the one that will move your revenue. If it isn't, we will say so.

30-minute call · No commitment · Custom quote in 48 hours

Process

How a Shopify Plus build runs

Conversion's four-stage growth process visualized in brand blue and green
01

Technical discovery

A structured audit of the theme and its customisations, the app stack, the integration landscape, the data layer, and the release process — plus the commercial context that determines what actually matters. The output is a scope that names its own unknowns.

02

Architecture and scope

Decisions recorded with their trade-offs: Liquid or headless, single store or expansion stores, which logic belongs in Functions, where B2B sits, what integrates in real time and what can reconcile nightly. Written down, because the reasoning is what future maintainers need.

03

Design and prototyping

Interface design against the real catalog and real content rather than placeholder copy, with the states that matter — out of stock, B2B pricing, multi-variant, long product titles — designed rather than discovered in QA.

04

Build

Two-week iterations in version control, with code review on anything touching checkout, pricing, or integrations. Work is demoed on staging at the end of each iteration so scope conversations happen against something real.

05

Integration and data

Systems connected with reconciliation, retry, and alerting built in from the start. Every integration gets a documented answer to the question of what happens when it fails, because it will.

06

QA and pre-launch

Cross-browser and cross-device testing, accessibility review, load testing where traffic patterns justify it, and a full SEO parity check against the URL inventory taken at discovery.

07

Launch

A rehearsed cutover with a rollback plan, DNS and redirect verification, and deliberate monitoring of indexation, Core Web Vitals, and error rates in the days that follow — not a check-in a month later.

08

Post-launch

Platform maintenance, incremental feature work, and a conversion testing programme run on real behavioural data. The last of these is a different discipline from development and is scoped separately.

Plus vs. standard Shopify

What the Plus tier actually unlocks

Worth being precise about, because a good deal of what brands assume requires Plus does not. Upgrading to solve a problem a lower plan already solves is an expensive way to not fix it.

FeatureShopify PlusShopify (Basic / Grow / Advanced)
CheckoutCheckout UI Extensions and Shopify Functions; versioned, sandboxed, upgrade-safeFixed checkout with limited configuration
Server-side logicFunctions for discounts, shipping, payment visibility, and cart transformsApp-based or client-side scripts
B2BNative company accounts, catalogs, price lists, and payment termsApps, discount codes, or a separate store
Additional storefrontsExpansion stores included on the Plus contractSeparate plans and separate billing
API limitsSubstantially higher, making real-time integration practicalStandard limits; batching required for heavy integration
AutomationShopify Flow with a wider trigger and action setLimited automation; more manual process
Typical build cost$50K–$250K depending on how much of the platform is used$15K–$50K for a custom theme build
Best suited toBrands whose roadmap depends on a specific Plus-only capabilityBrands whose constraints are design, content, or marketing rather than platform

Sectors

Where the complexity tends to sit

Different categories push complexity into different parts of the build. Knowing where it will land changes how a project is scoped.

Fashion and apparel

High variant counts, returns-heavy economics, and merchandising that changes weekly. The engineering priorities are variant and size-guide UX, fast collection filtering, and a theme merchandisers can operate without a developer in the loop.

Beauty and personal care

Subscription and replenishment mechanics, regulated ingredient and claims content, and heavy reliance on reviews and UGC. Subscription logic and its interaction with discounts and shipping is usually the most delicate part of the build.

Food and beverage

Perishability, delivery windows, and regional restrictions push complexity into shipping and fulfilment logic — a natural fit for Shopify Functions controlling delivery method availability by zone, date, and product.

Home and furniture

High average order values, freight and white-glove delivery, and long consideration cycles. Configurators, room visualisation, and finance options tend to dominate scope, alongside shipping logic that reflects real freight cost.

Health and supplements

Subscriptions, compliance-sensitive claims, and bundle economics. Bundling and subscription discount logic implemented in Functions rather than in apps tends to be more predictable and easier to reason about.

Electronics and technical products

Deep specification data, compatibility rules, and warranty and registration flows. This is usually a PIM integration problem before it is a storefront problem, and scoping it as a storefront problem is a common mistake.

B2B and wholesale

Company accounts, negotiated pricing, net terms, and reorder workflows — the area where Plus most clearly justifies its cost, because the alternative is manual process that does not scale.

Multi-brand groups

Several brands under one commercial entity, where expansion stores, shared component libraries, and centralised operational tooling reduce duplicated effort — provided the decision about what is shared is made deliberately at the start.

International and multi-market

Multi-currency and multi-language through Markets, with domain strategy, hreflang, local payment methods, and duty handling treated as architecture rather than as configuration applied late.

Deliverables

What you get

Scope varies by engagement. This is the shape of a full Plus build.

Everything included in a Conversion engagement, laid out as tangible deliverables

Engineering

  • Liquid theme in version control with a documented branching model
  • Checkout UI Extensions in supported checkout slots
  • Shopify Functions for discount, shipping, payment, and cart logic
  • Custom or private apps where off-the-shelf does not fit
  • Staging environment mirroring production
  • Code review on checkout, pricing, and integration changes

Commerce configuration

  • B2B company accounts, catalogs, and price lists
  • Markets configuration for currency, language, and regional catalog
  • Expansion store setup and shared-code strategy
  • Shopify Flow automations for operational process
  • Metafield and metaobject content model
  • App stack audit and consolidation plan

Data and integration

  • ERP, PIM, or OMS integration with reconciliation and alerting
  • Documented failure behaviour for every integration
  • GA4 and server-side tagging with a consistent event schema
  • Ad platform conversion configuration
  • Order and inventory data reconciliation process

Launch and handover

  • URL inventory and redirect map built from a full pre-change crawl
  • SEO parity check on titles, metadata, structured data, and internal linking
  • Accessibility review
  • Core Web Vitals measured on field data
  • Rehearsed cutover with a rollback plan
  • Technical documentation and team walkthrough

Why Conversion

How we work

We will talk you out of the wrong build

The most expensive Plus projects are the ones that solve a problem the brand did not have. If your constraint is merchandising, content, or acquisition rather than platform, a rebuild will not fix it, and we would rather say so at the scoping stage than eighteen weeks in.

Process before portfolio

Version control, staging, code review, and a reversible deploy path are what make a Plus store maintainable. They are invisible in a case study and decisive in year two.

Integration treated as the hard part

Front-end work is estimable. Integration is where Plus projects actually slip, so we scope it as discovery rather than as a fixed-price assumption about a system we have not seen.

Conversion literacy, not just delivery

We build storefronts and we run conversion programmes, which means the build is informed by what actually changes behaviour rather than by what photographs well.

Honest about headless

Hydrogen is a genuine capability and a genuine trade. We will recommend it when the front-end requirement justifies the operational cost and tell you when it does not.

Documentation as a deliverable

A build you cannot hand to another team is not finished. Architecture decisions, integration behaviour, and release process are written down and walked through.

Questions

Shopify Plus development, answered

What does a Shopify Plus development agency actually do?
A Shopify Plus development agency builds and maintains stores on Shopify's enterprise plan, which means working with the parts of the platform that are not available on Basic, Grow, or Advanced. In practice that is checkout extensibility — Checkout UI Extensions, Shopify Functions, and branded one-page checkout — plus B2B on Shopify with company accounts and price lists, up to nine additional expansion stores on a single Plus contract, Shopify Flow automation, and higher API rate limits for integration work. A Plus development agency also owns the surrounding engineering: theme architecture, custom apps, ERP and PIM integrations, data layer and analytics, performance, accessibility, and the release process that keeps all of it deployable without breaking the storefront.
How is a Shopify Plus development agency different from a regular Shopify agency?
The difference is scope of platform access and scope of engineering risk. A standard Shopify agency works within themes, apps, and the Admin API — a large surface, but one where the checkout is fixed and the store is a single instance. A Plus agency works in a codebase where checkout is programmable, where Functions run server-side logic on discounts, shipping, payment, and cart transforms, where B2B and DTC can share one instance with different pricing and terms, and where an expansion store strategy introduces multi-store content and inventory decisions. That changes the discipline required: versioned deployments, staging environments, code review, and rollback plans stop being optional. Most stores that outgrow a standard agency outgrow it on process, not on design ability.
How much does Shopify Plus development cost?
Market ranges in the US and UK are roughly $50,000 to $250,000 for a full Shopify Plus build, depending on how much of the enterprise surface you actually use. A Plus build that is essentially a well-engineered theme with a few checkout extensions sits at the low end. A build with B2B company accounts, ERP-synced pricing, multiple Functions, several expansion stores, and a custom app sits at the high end. Headless Hydrogen builds typically start higher because you are taking on a front-end application in addition to the commerce layer. Separately, Shopify's own Plus platform fee is a licence cost paid to Shopify, not to your agency — see our Shopify Plus pricing guide for current published rates.
How long does a Shopify Plus build take?
A focused Plus build runs about 12 to 16 weeks. A build that includes B2B, ERP integration, custom Functions, and multiple markets runs 16 to 24 weeks. The variable that moves this most is not design or front-end engineering — it is integration. Getting clean, reliable data out of an ERP, PIM, or OMS is routinely the longest pole in the tent, and it is the part most likely to be underestimated at scoping. A credible Plus agency will ask to see your integration landscape before quoting a timeline, and will treat any system it has not seen as a discovery item rather than a fixed-price assumption.
Do I need Shopify Plus to get these features?
Some of them, yes. Checkout UI Extensions, Shopify Functions on checkout, B2B on Shopify, expansion stores, and the higher API limits are Plus-tier capabilities. But a large share of what brands assume requires Plus does not: custom theme architecture, most app integrations, a strong PDP and cart experience, subscriptions, internationalisation through Markets, and the vast majority of CRO work are all available on lower plans. It is worth being honest about this, because upgrading to Plus to solve a problem that a lower plan already solves is an expensive way to not fix the problem. If you are weighing the upgrade, the useful question is which specific Plus-only capability your roadmap depends on in the next twelve months.
What is checkout extensibility and why does it matter for development?
Checkout extensibility is Shopify's replacement for checkout.liquid. Rather than editing checkout markup directly, you extend checkout through Checkout UI Extensions — sandboxed components that render in defined slots — and through Shopify Functions, which run server-side logic for discounts, shipping methods, payment method visibility, and cart transforms. The practical consequence for development is significant: checkout customisations are now versioned, upgrade-safe, and reviewable, instead of being a fork of Shopify's own checkout that breaks on every platform update. Brands still running legacy checkout.liquid customisations are on borrowed time and should treat migration as a scheduled project rather than an emergency.
Can you work with our existing internal development team?
Yes, and on Plus builds it is common. The arrangements that work tend to have clear ownership boundaries: one team owns the theme and storefront, the other owns integrations or the internal systems those integrations touch, and both work from the same ticket tracker, the same staging environment, and the same definition of done. The arrangements that fail are usually the ones where ownership is shared without being defined, and two teams deploy to the same theme without a shared release process. We will ask about your branching model, your review process, and your deploy cadence early, because a mismatch there costs more than a mismatch in tooling.
What happens after launch?
Launch is when the actual data starts. A Plus store generates enough traffic that the questions you could only answer with judgement before launch become answerable with evidence after it — which checkout extension is helping, whether the B2B flow is being completed, where mobile is losing people. Post-launch work usually splits into three streams: stability and platform maintenance, incremental feature work, and conversion optimisation informed by real behaviour. The last of those is a different discipline from development, and is usually better run as a testing programme than as a backlog of changes someone felt strongly about.
Do you build headless Hydrogen storefronts on Plus?
Yes, when the case for it is real. Hydrogen and Oxygen make sense when you need front-end capabilities that Liquid genuinely cannot deliver — deeply custom interaction, a content model that outgrows the theme, or an app-like experience where the storefront is one of several consumers of the same commerce API. They make much less sense as a default, because going headless moves a large amount of previously-managed complexity onto your team: rendering, caching, preview, SEO, and the loss of the theme editor for merchandisers. The honest framing is that headless is a trade, not an upgrade. We will tell you when we think the trade is bad.
How do you handle B2B and DTC on the same store?
B2B on Shopify lets a single Plus instance serve both audiences: company accounts with multiple buyers and locations, per-company catalogs and price lists, payment terms, and quantity rules, all running against the same product data as the DTC storefront. The development work is mostly in the seams — theme logic that behaves differently for a logged-in B2B buyer, ERP-driven pricing that has to stay accurate, and a checkout that respects net terms. The alternative, running a separate wholesale store, is sometimes still the right answer when the two businesses genuinely share nothing but the catalog. That is a business-model question first and an architecture question second.
What does the discovery phase involve?
Discovery on a Plus build is mostly an inventory of what already exists and what constrains it. That means the current theme and its customisations, the app stack and which apps are load-bearing, the integration landscape and who owns each system, the analytics and data layer, the content model, and the release process. It also means the commercial context: which markets, which channels, which parts of the roadmap are committed. The output is a scope with the uncertain parts named as uncertain. A scope with no unknowns in it is not a more confident scope, it is a less honest one.
How do you protect SEO during a Shopify Plus rebuild?
By treating it as an engineering requirement rather than a post-launch checklist. That means a full crawl and URL inventory before anything changes, a redirect map built from that inventory rather than from assumptions, parity checks on titles, metadata, structured data, and internal linking, and a staged launch where indexation, Core Web Vitals, and Search Console coverage are monitored deliberately in the weeks after cutover rather than looked at when traffic drops. Most rebuild traffic losses are not mysterious. They are redirect maps that missed a template, or a change in internal linking that quietly orphaned a section of the catalog.

Related

Explore related services

Shopify Plus development rarely runs in isolation. These are the adjacent areas it usually touches.

Shopify Plus Agency

Strategy and growth on the Plus platform, beyond the build itself.

Explore

Shopify Development Agency

Custom theme and app development across every Shopify plan.

Explore

Shopify App Development

Custom and private apps against the Admin and Storefront APIs.

Explore

B2B Ecommerce Agency

Company accounts, price lists, net terms, and ERP-synced wholesale.

Explore

Shopify Migration Agency

Replatforming to Shopify Plus without losing search equity.

Explore

Shopify Checkout Optimization

Checkout extensibility work aimed at the step closest to revenue.

Explore

Next step

Tell us what you are trying to build

A 30-minute call, an honest read on whether Plus is the right answer, and a scope that names its own unknowns.

No credit card · No commitment · Pay only on results