CUSTOM SHOPIFY APPS

Custom Shopify app development for stores that outgrew the App Store.

For Shopify and Shopify Plus merchants whose operations need logic no off-the-shelf app provides. We build custom and private apps for inventory sync, order routing, returns, and back-office workflows, then maintain them long-term.

Built around your exact workflow
Proven at 200,000+ SKUs
Maintained by the team that built it

10+ years · systems trusted on 32M+ transactions

18.5M+

Transactions processed

200,000+

SKUs managed

////WE’VETRUSTED BY

SOUND FAMILIAR?

Your store runs on apps that almost do what you need.

You stack several apps to cover one workflow, and they don't share data.
Inventory drifts between stores, warehouses, and supplier feeds.
Orders need routing to warehouses or suppliers, and it happens by hand.
Your returns rules are too specific for a standard returns app.
Someone exports CSVs every week to reconcile what Shopify shows.
You need logic that no app in the Shopify App Store offers.

WHY CHOOSE STACKWORX

Shopify apps built like production software

A custom Shopify app is software your business depends on every day. We build it like any production system: tested, monitored, and maintained.

Fit to your operation

We learn how orders, stock, and returns actually move through your business before designing the app.

Built for volume

Our Shopify work for Midway Sports runs across 200,000+ SKUs and 18.5M+ transactions.

Shopify Plus ready

Private apps, admin extensions, and checkout UI extensions for Shopify Plus stores.

WHAT YOU GET

Everything a custom Shopify app can take over

01Flagship

Custom & private Shopify apps

Apps built around the exact logic your operation runs on.

Private apps
Extensions
Checkout UI

Inventory sync across stores

Shopify inventory sync across multiple stores, locations, and supplier feeds.

Order routing

Shopify order routing to warehouses, suppliers, and manufacturer-direct partners.

Returns & exchanges

Eligibility checks, return tracking, and rules that match your policy.

AI product recommendations

Recommendations built into the storefront, not a bolt-on popup.

Ops dashboards & reporting

Internal tools and reporting your team uses to run the store day to day.

18.5M+
Transactions processed
200,000+
SKUs managed
5
Stores synced in real time
10+ yrs
In production

Proof · Midway Sports

A Shopify operation running 200,000+ SKUs.

Order and inventory management, manufacturer-direct shipments, self-service return tracking, and AI product recommendations for Midway Sports, behind 18.5M+ transactions.

200,000+SKUs managed

Book a Discovery Call

Midway Sports order and inventory management system

HOW IT WORKS

From first call to a live Shopify app.

01
Discovery call
A 45-minute call on how your store actually runs today.
02
Map & scope
We map the workflow and scope the smallest high-impact app.
03
Build
Working software in increments, so you see progress early.
04
Own it
We maintain and extend the app long-term as your store grows.

WHAT CLIENTS SAY

Partners, not vendors

Farooq did an excellent job with our Shopify inventory sync integration.

elena_nevex

Fiverr client, United States

Verified on Upwork

FAQS

Before You Get Started

What does Stackworx do?

We build and take ownership of the systems your business runs on: custom Shopify apps, Ruby on Rails platforms, third-party integrations, and practical AI workflows. Most clients come to us when off-the-shelf apps and quick fixes stop scaling.

Do you only build new products, or can you take over an existing system?

Both. A large part of our work is taking over existing Rails and Shopify codebases, stabilizing them, and then extending them. We start with a technical audit so you know exactly what you have before anything changes.

How do you add AI to a business that already has software?

We add AI inside the systems you already run rather than bolting on a separate tool. Typical work includes content generation, document and data extraction, product recommendations, and support automation, shipped as a focused AI Integration Sprint with measurable outcomes.

How do engagements usually start?

Most clients start with a Technical Audit or an AI Integration Sprint. From there we move to an MVP build or a dedicated product team on a monthly retainer, depending on how much ongoing work you have.

Which industries do you work with?

Mostly ecommerce brands on Shopify and SaaS companies in PropTech, InsurTech, and FinTech. Our platforms have processed 32M+ transactions and serve 20,000+ real estate agents.

Where is your team, and how do you work with US clients?

Our senior engineering team is based in Lahore, Pakistan, and we contract with US clients through Stackworx LLC, our Wyoming company. We work across time zones with regular overlap hours, async updates, and long-term ownership of the systems we build.

Ready to build past off-the-shelf apps?

Tell us what your store needs to do that it can't today. In a 45-minute Systems Discovery Call we map the right build, whether you hire us or not.