Treevoxa offers Shopify app development services for merchants whose store needs to do something Shopify and the App Store do not: keep stock in step with a shop counter or warehouse system, push orders into an ERP, apply pricing rules, or automate fulfilment. We do custom Shopify app development on Shopify's APIs, and we understand the hard part of commerce software because we run online stores on the same stock as a counter in PharmaFlow.
Shopify app development agency: what we build
- Inventory sync between Shopify and your POS, ERP or warehouse, so an item is never sold twice.
- Order and fulfilment flows into your back office, courier or 3PL.
- Pricing and catalogue tools: bulk updates, customer-specific prices and product data from your ERP.
- Reports that combine Shopify data with costs and stock from your other systems.
- Admin extensions that put the tools your team needs inside the Shopify admin.
The problem we already solve: one stock record
In PharmaFlow, a counter sale and an online order come off the same batch-by-batch stock, earliest expiry first, so the last item is never sold twice. A Shopify integration faces the same problem with more moving parts: webhooks arrive out of order, APIs have rate limits, and two systems both think they own the stock. We design the sync with one system as the source of truth, idempotent updates, retries and a reconciliation report, so mismatches are caught by the system, not by a customer. See POS software development for the counter side.
How we build Shopify apps
- Map the data. Which system owns products, prices, stock, orders and customers.
- Choose the APIs and webhooks, and plan for their rate limits.
- Build the app with a small back end that stores only what it must.
- Test on a development store with your real catalogue and order patterns.
- Install, monitor and support under a written agreement.
Tech stack for Shopify app projects
| Part | What we use |
|---|---|
| App back end | Node.js (NestJS, Express) or Python (FastAPI) |
| Admin UI | React |
| Integration | Shopify Admin API and webhooks, your systems' APIs |
| Data | PostgreSQL |
See API development services and Node.js development for how we build integrations.
Shopify app development cost
The cost of a Shopify app depends on how many systems it connects, how much data it syncs, whether it needs its own admin screens, and whether it is a custom app for one store or a public app for many. Public apps cost more because they need billing, multi-store support and App Store review. Our custom software development cost guide explains how quotes are built. We quote in US dollars, in writing.
Engagement models for Shopify app work
- Fixed scope for a defined app or integration.
- Dedicated developer for ongoing store engineering. See hire dedicated developers.
- Hourly for fixes and small changes.
Who Shopify app development is for
- Merchants with an ERP or warehouse system that must stay in step with Shopify.
- Brands with B2B customers who need customer-specific prices or ordering rules.
- Retailers with shops and a Shopify store that must share stock.
- Agencies and software companies building an app for the Shopify App Store.
Shopify integration pitfalls we avoid
- Two owners for the same data. One system owns each field; the other follows.
- Ignoring rate limits. Bulk updates are queued and paced.
- Trusting webhooks to arrive once, in order. Updates are idempotent and checked against current state.
- No reconciliation. A daily report lists anything that did not sync.
What to send us for a Shopify app quote
Your store, the systems it must connect to, which system owns products, prices, stock and orders, and the problem you need solved.
Questions to ask before you hire a Shopify developer
- Which system will own each field: products, prices, stock and orders?
- How do you handle rate limits and duplicate webhooks?
- What does the reconciliation report show?
- Custom app or public app for our case, and why?
- Who hosts the app and owns the code?
Ask every bidder the same questions, in writing, and compare the answers before you compare the prices.
Working across time zones on Shopify app projects
We work remotely with a daily overlap window in your working hours, agreed before the project starts. Releases are scheduled outside your peak trading hours.