Shopify Plus Development Agency
Shopify Plus Development Agency Built For Enterprise Trading
Most stores reach Plus because they outgrew the tier below it, then keep building as if nothing changed. We take the store from discovery through checkout, apps and launch, then hold it through peak. Stallyons is a Delaware-registered US company and every release goes through the same review.
Triple Protection Guarantee
- US-Registered Entity
- Signed IP Assignment
- Senior Engineers Only
Triple Protection Guarantee:
- US-Registered Entity
- Signed IP Assignment
- Senior Engineers Only
Years In Business
0
+
Engineers On Staff
0
+
Avg. Engineer Exp.
0
+
Where Plus Pays Off
Checkout Editing
Extensible
Shopify Functions
Server-Side
Expansion Stores
One Admin
Wholesale B2B
Price Lists
Peak Traffic
Sale Ready
Apps We Build
Private Apps
Theme Engineering
Own The Code
Launch Windows Agreed
Around BFCM
Integrations
ERP Linked
IP Assignment
Signed
Delivery Overlap
Fixed
Hours
Code & IP Owner
You
Trusted By Startups
What A Shopify Plus Development Agency Delivers
Plus is not a bigger version of the same store. It opens the checkout to code, replaces the old Scripts model with Functions that run on Shopify's own infrastructure, adds B2B and expansion stores inside one admin, and lifts the API limits that shaped how the previous build was written. A Plus store therefore needs engineering decisions, not another theme. Which of those capabilities you actually use is the thing worth getting right early.
Stallyons is a Shopify Plus Partner, registered in Delaware as a US company, and our engineers work inside a time-zone window agreed before the project starts, with four-plus hours of daily overlap. You sign a US contract, run diligence on a US entity and pay one US invoice. Behind the work sits twelve-plus years of delivery across six continents and around thirty-five engineers, averaging four-plus years of production experience. Merchants, heads of ecommerce and CTOs across North America, the UK, Europe, the Middle East and Asia-Pacific bring us the build.
What Shopify Plus Work Covers
Checkout built as code, not as a workaround: extensions for upsells, delivery rules, custom fields and branding, deployed through the same release process as everything else and versioned where you can read the history.
Shopify Functions in place of legacy Scripts: discount, shipping and payment logic that runs server-side on Shopify's own infrastructure, so complex pricing rules survive traffic instead of buckling under it.
Expansion stores that stay one business: new regions, brands or currencies launched as their own storefronts, sharing a catalogue strategy and one admin rather than becoming three sites to maintain.
Custom apps against Plus-tier APIs: embedded admin tools, private integrations and the higher call limits that make bulk operations and catalogue sync realistic rather than theoretical.
Theme engineering at Plus scale: Online Store 2.0 sections your merchandising team can use without a developer, and templates that still render fast on a deep catalogue.
A launch scheduled around trading: release windows agreed against your calendar, load rehearsed before the traffic arrives, and a code freeze written into the plan rather than negotiated on the day.
Why Enterprise Merchants Choose Our Shopify Plus Team
- Ask which Plus capabilities the build will actually use. An agency that answers "all of them" has not read your catalogue, your margins or your order volume yet.
- Get the checkout approach in writing. Extensions and Functions age differently from theme hacks, and the difference decides what you have to rebuild in two years.
- Ask how many custom apps the build needs. Every app is code somebody has to own after launch, and nobody tells you that at the proposal stage.
- Agree the launch window before contracting. A go-live three weeks into peak trading is a decision, not an accident, and it should be made with your calendar on the table.
- Check where the store lives. The Shopify org, the repositories, the app credentials and the CI pipeline should be in your accounts from the first week, not ours.
- Insist on a written handover: theme structure, app inventory, Function logic and release steps documented as the work happens, so the next team reads instead of guessing.
How A Shopify Plus Build Starts With Us
Every project starts with a free 45-minute scoping session. No slide deck, no sales script. You bring the store, the catalogue and the constraints; you leave with a recommended Plus architecture, a scope and a timeline.
We are selective about new projects and cap how many we run at once, because the scoping is the product. If your volume does not justify Plus yet, we will say so on that first call rather than after.
Why Clients Choose Us
Full
Written IP Transfer
USA
Contract Entity
Yours
Store, Apps, Repos
Named
Delivery Lead
Ready to get your Shopify Plus build done properly?
What We Build On Shopify Plus
Shopify Plus Development Projects We Deliver
Plus earns its cost when the store does something the tier below cannot. These are the builds we deliver most often, each with an agreed scope, an agreed launch window and the same review standard on every merge.
Checkout Extensibility
UI extensions, branding, validation
In Checkout
Shopify Functions
Discounts, shipping, payments
Server-Side Fn
Expansion Stores
New markets, brands and currencies
One Admin
B2B On Shopify Plus
Company accounts, price lists
Wholesale Enabled
Custom Apps
Embedded, private, Plus APIs
Admin-Level
Theme Engineering
Online Store 2.0, sections
Editable
Systems Integration
ERP, PIM, WMS and tax engines
Linked
Peak Trading Prep
Load testing, freeze windows, cover
Sign-Off
Migration To Plus
From Advanced or another platform
Data Intact
Support & Maintenance
Monitoring, fixes, releases, cover
Kept Running
Not sure what belongs on Plus? Let's map it out together.
Common Challenges
Why Do Shopify Plus Builds Stall?
Six patterns behind almost every Plus store that costs more to run than it should. None of them are the platform's fault.
Scripts Deadline
01
Discount and shipping logic still sits in the legacy Scripts model nobody has rewritten. The rules work until the day they do not, and by then the person who wrote them has moved on twice.
Apps Instead Of Code
02
Each new requirement gets solved by installing something. Thirty apps later the storefront is slow, the monthly bill is real, and two of them do the same job.
One Store For All
03
Three regions, three tax models and three languages get forced through one storefront. Every merchandising change then needs a conditional nobody remembers.
No Peak Rehearsal
04
The busiest four hours of the year are the first time the new checkout meets real traffic. Nobody load-tested it, and the fix has to ship while orders are coming in.
Checkout Left Untouched
05
The one thing Plus unlocks is the one thing the build never used. Upsells, delivery rules and B2B terms stay outside the checkout, where you never see the orders you lost.
Nobody Owns The Store
06
The build finishes and the store drifts. App updates, theme edits and Function changes land untracked, until nobody can say what is in production.
Recognise the pattern? Let's plan it properly.
Shopify Plus Services
Six Shopify Plus Development Services
Six ways to buy Plus delivery from one accountable vendor. Run one, or run several in parallel under a single contract.
Checkout & Functions Builds
01
Checkout extensions and Shopify Functions designed together: upsells, delivery rules, custom fields and discount logic, specified and approved before a line of it is written.
Custom Shopify Apps
02
Embedded admin tools and private integrations built against Plus-tier API limits, so bulk catalogue work and order sync run at your volume rather than at the demo's volume.
Expansion Store Rollouts
03
New regions, brands and currencies launched as their own storefronts, with a shared catalogue strategy so the estate stays one business to run.
B2B On Plus Enablement
04
Company accounts, buyer roles and catalogue-level price lists configured on the Plus B2B model, running beside your direct-to-consumer storefront.
Moving The Store To Plus
05
Stores brought up onto the Plus tier and rebuilt to use what it opens: Functions, checkout extensions, higher API limits and the B2B model where it earns.
Plus Support & Peak Cover
06
Theme and app maintenance, Function changes, monitoring and agreed cover through your trading peaks, on a standing cadence rather than as emergency work.
Not sure which Shopify Plus service fits? Let's scope it.
Why Choose Us
What Makes Our Shopify Plus Development Different
The details that decide whether a Plus store is still cheap to change in its third year.
A US Legal Entity
01
Stallyons is registered in Delaware. Your contract, your invoice and your legal recourse sit with a US company, not an unknown one.
Shopify Plus Partner
02
As a Shopify Plus Partner, we build with Functions, checkout extensions and Plus APIs rather than stacking apps you cannot change later.
Overlap You Set
03
You choose the hours we share with your working day, and stand-ups, reviews and escalations all happen inside that window.
Peak-Aware Releases
04
Launch windows and code freezes are agreed against your trading calendar during scoping, not argued about in the week before your busiest weekend.
Reviewed Code
05
Every merge is reviewed against an agreed definition of done, on your board, where you can read it yourself.
One Contract
06
One contract covers the engagement, so procurement, legal and finance each deal with a single named counterparty.
Ready to see how we run a Shopify Plus project?
Our Process
From First Call To Your Shopify Plus Launch Day
A delivery process built to surface catalogue, checkout and traffic risk before any code.
Discovery
Understand the catalogue, volume and systems
Scoping
Agree scope, milestones and cost structure
Design
Checkout flows, theme and data model agreed
Contracting
NDA, IP assignment, access and onboarding
Deliver
Work on your board, reviewed on merge
Launch & Trade
Release, monitor and cover peak trading
Want to see how this maps to your roadmap?
Technology Stack
The Stack Behind Our Shopify Plus Development
The Plus toolchain we build stores with, from the checkout and Functions layer to what runs beside it.
Shopify Plus
Shopify Plus Core
GraphQL Admin
Storefront API
Liquid / OS2
Metaobjects
Checkout & Functions
Checkout UI
Shopify Functions
Discount Fns
Branding
Validation & Rules
Apps & Extend
Remix App Stack
Node & GraphQL
React & Polaris Admin
TypeScript 5
Webhooks & Flow Rules
Data & Commerce
Product Catalog
PostgreSQL
Mongo Stores
Search & Filtering
Markets & Payments
Cloud & DevOps
AWS / GCP / Azure
Docker / K8s
Shopify CLI/CI
GitHub Actions / CI
Datadog / Grafana
Industries We Serve
Shopify Plus Development For High-Volume Retail Brands
Engineers who already know your margin rules, returns policy and peak patterns spend month one building, not asking.
Fashion & Apparel
Sizes, variants, returns, drops
Beauty & Personal Care
Subscriptions, bundles, samples
Food & Beverage DTC
Perishables, delivery windows
Home & Furniture
Large baskets, freight, lead times
Electronics & Hardware
Warranties, bundles, spare parts
Health & Supplements DTC
Compliance, batches, reorders
Sports & Outdoors
Seasonal peaks, kit builders
Wholesale & Multi-Brand
Expansion stores per brand
We know your category. Let's scope the Plus build.
How We Compare
Shopify Plus Agency vs Freelance vs In-House
An honest look at how the options compare.
| Capability | In-House Team | Freelance Developer | Generalist Web Agency | Stallyons Technologies |
|---|---|---|---|---|
| Checkout approach | Whatever shipped first | ✕ Theme workaround | App-driven | Extensions and Functions |
| Legacy Scripts | Still running | ✕ Not touched | Quoted separately | Rewritten as Functions |
| Custom app work | Depends on capacity | ✕ Rarely offered | Installed, not built | Built on Plus APIs |
| Multi-store estate | Grown ad hoc | ✕ Single store only | Duplicate themes | Expansion stores planned |
| B2B alongside DTC | Separate system | ✕ Out of scope | Third-party app | Native Plus B2B model |
| Peak trading readiness | Hoped for | ✕ No cover | Freeze on request | Rehearsed, freeze agreed |
| Contracting entity | Your payroll | ✕ Platform terms | Local entity | US-registered LLC |
| Store & repo ownership | Internal only | ✕ On request | At project end | Your accounts from day one |
See the difference for yourself
Complete Engagement
Everything Included In A Shopify Plus Development Project
From Scoping to Contracting to Delivery, One Vendor
Here's everything included in a Shopify Plus development project:
One Shopify Plus Project Price: No Hidden Fees, No Surprises.
Every Shopify Plus project includes all eight components above. One contract, one senior team, one predictable cost, and no vendor sprawl.
🔒 No obligation. We'll deliver a detailed proposal within 48 hours.
Plus, Get These Free Bonuses
Free Plus Store Review
A written read on which Plus capabilities your store should be using, which apps are earning their place, and where the checkout is costing you orders. Yours to keep.
Included Free
Delivery Plan & Estimate
A phased delivery plan with scope, milestones, a stack recommendation and a transparent, itemized estimate for the engagement.
Included Free
Free Scoping Checklist
The questions we would ask any Plus team about checkout, Functions, apps and launch windows, so you can put us through the same test.
Included Free
Risk-Free Partnership
Our Shopify Plus Delivery Promise
We stand behind every engagement with commitments that protect your investment.
01
Scope Agreed First
Scope, model, working hours and cost structure are written down and agreed before contracting, so nothing is discovered later.
02
Built to Last
Senior developers, code review, automated tests, security and accessibility audits, and clean, documented code you fully own.
03
IP And Access Protected
NDA and IP assignment are signed before access, permissions are scoped per person, and your accounts stay under your control.
Start your Shopify Plus build with confidence, backed by our Triple Protection Guarantee.
Track Record
Engagements That Ship, Scale, and Compound
500+
Projects Delivered
29+
Service Categories
81%
Repeat Client Rate
4.9 ★
Clutch Rating
"We came to Stallyons after burning two years and four vendors on a multi-platform launch that kept slipping. They scoped it end-to-end — web app, iOS, Android, an AI summarization layer, and a Shopify integration — and shipped it in 22 weeks. One team, one budget, one quality bar. We've handed them three more engagements since."
Mark Sawyer
CEO/Founder
PlatinumLED
"Stallyons rebuilt our customer-facing portal, integrated three legacy systems, shipped an AI document analysis pipeline, and brought our compliance posture to SOC 2 — all under one engagement. The senior engineers on the team have shipped at companies five times our size. It's the best vendor decision we've made in a decade."
Mark Sawyer
CEO/Founder
PlatinumLED
FAQ
Frequently Asked Shopify Plus Development Questions
A Shopify Plus development agency designs, builds and runs stores on Shopify’s enterprise tier rather than supplying people to do it. Stallyons is a Shopify Plus Partner. The work covers scoping, checkout extensions and Functions, custom apps against Plus-tier APIs, theme engineering, expansion stores, B2B configuration and the launch itself, then support once the store is trading. What you buy is a working store with a written scope behind it.
On the standard plans the checkout is closed and the API limits are lower, so most requirements are met by installing apps and editing the theme. Plus opens the checkout to extensions, replaces the old Scripts model with Functions that run server-side, raises the API ceilings, and adds native B2B and expansion stores in one admin. That changes what a build should be made of, which is why the engineering decisions differ.
Cost follows scope, catalogue complexity and how much custom checkout and app work is involved, so anyone quoting a figure before scoping is guessing. What moves it most is the number of storefronts, whether B2B is in scope, and how many systems have to be integrated. We scope first, then price it, and itemise what each phase covers.
It depends on the scope, and we put a timeline in writing before contracting rather than quoting a stock number. What changes the answer most is catalogue size, how many integrations exist, and whether the design work is done. We deliver in phases against milestones you sign off, and we schedule the launch away from your trading peaks.
It is Shopify’s supported way of changing the checkout with code instead of theme edits. Extensions add fields, upsells, delivery options and branding at defined points, and Functions handle discount, shipping and payment logic server-side. Because both are versioned and deployed, they survive platform updates.
Yes, and the move is treated as a rebuild of what the tier unlocks rather than a plan change. We audit the theme, the app stack and the Scripts still in use, then decide what becomes a Function, what becomes an extension and what should stop existing. The catalogue and order history come across intact.
Yes. Plus carries a native B2B model with company accounts, buyer roles, payment terms and catalogue-level price lists, so wholesale can run beside your direct storefront in one admin. We configure it during scoping, because the pricing structure affects the catalogue design and the checkout rules around it.
You do, from the first commit. The NDA and IP assignment are signed before any access is granted, with no licence-back and no shared ownership. The Shopify organisation, the repositories, the app credentials and the deployment pipeline are created in your own accounts, so nothing needs handing back later.
Still have questions? Let's talk.
Schedule an appointment with us today!
Ready To Get Your Shopify Plus Store Built Right?
Get a free consultation. We'll review your store, recommend a Plus architecture, and send a detailed written proposal.
