02Our Integration Process
From Fulfillment Mapping to Live Sync in Five Steps
You see exactly how FBA, FBM, and returns will be routed before development starts, not just a finished sync at the end.
05Projects We've Built
Ecommerce Projects We Have Built
A selection of Shopify and ecommerce builds shipped for clients, several involving backend inventory and channel integrations like this one.
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06What Our Clients Say
What Clients Say After Launch
Feedback from ecommerce teams we have built inventory and channel integrations for.
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We had a different kind of problem. People were visiting the store, adding products to their carts, and then disappearing before they finished the order. We had tried a few apps and made changes here and there, but nothing really seemed to solve the bigger issue. The team went through the shopping experience with us and pointed out things we hadn't really noticed ourselves. They cleaned up the cart and checkout flow, made the mobile experience much smoother, and helped us make the store feel easier to shop. I’m not going to pretend we fixed everything overnight, but it finally feels like the store is helping the sale instead of getting in the way of it.
Ethan Parker
Founder of Elite Academy
The mobile experience is probably my favourite part of the new site. We had spent a lot of time making sure the desktop version looked right, and the team kept pushing us to think about how everything would actually feel on a phone too. They were right. The navigation is clean, the interactions feel natural, and everything we’ve tested so far works exactly as it should. They also went through the links, forms, integrations, and other details more than once before launch, which I really appreciated. And even after going live, we could still reach out when something came up. The whole process felt friendly, organised, and surprisingly straightforward.
James Whitmore
Head of Marketing of Lumen Outdoor
We had a pretty specific idea of what we wanted our website to become, but I wasn’t sure how easily we could explain all of it to a development team. There were quite a few moving parts, and we were working toward a deadline, so I expected a few things to get lost along the way. That never really happened. They understood what we were trying to achieve, kept us updated throughout the process, and got everything ready within the agreed timeline. The final site feels much easier to navigate, works beautifully on mobile, and is noticeably smoother for our customers. It was a huge relief seeing the original idea actually turn into the website we had in mind.
Michael Bennett
Founder & CEO of Northbridge Consulting
150+
Projects shipped
10+
Years in development
Top 3%
Upwork Top Rated Plus
5★
Average review score
07Work Culture
Why Businesses Trust Us With Amazon Integrations
An Amazon integration touches live inventory across two channels, so accuracy is not optional. These are the habits we bring to every project.
Fulfillment mix mapped first
FBA, FBM, or both, we design the sync around how you actually fulfill orders, not a generic template.
Buffer stock built in
Safety stock levels account for Amazon's own sync delays, so a fast-moving SKU doesn't oversell before the count catches up.
Returns and cancellations included
Amazon returns and cancellations flow back to Shopify instead of creating an inventory blind spot.
Tested before it's live
Sandbox testing with real order and inventory data before your live store and Amazon account are connected.
Clear on what's included
You know exactly which listings, SKUs, and order types sync before development starts.
Built to be maintained
Documentation and an optional retainer so the sync keeps working as Amazon's and Shopify's APIs change.
08Overview
Who builds custom Shopify Amazon integrations that prevent overselling across FBA and FBM?
DeveloperLook builds custom Shopify Amazon integrations that sync inventory, orders, and listings in real time, with buffer stock and fulfillment routing that keeps FBA and FBM from overselling each other. Projects start from $1,999, most complete in 2 to 6 weeks, and we recommend a connector app first if your setup is simple enough for one.
- Service
- Custom Shopify Amazon integration
- Starting price
- From $1,999 USD, fixed scope after a project brief
- Typical timeline
- 2 to 6 weeks
- Platform
- Shopify, Shopify Plus, Amazon Seller Central (FBA & FBM)
- Built with
- Amazon Selling Partner API (SP-API), Shopify Admin API
- Experience
- 10+ years and 150+ shipped projects
- Post-launch support
- 30 days included, then optional retainer
- Communication
- Calls in US, UK, and AU business hours
Who it's for
Shopify stores selling on Amazon FBA and FBM together
You fulfill some Amazon orders through FBA and others yourself, and need inventory to reflect both correctly without overselling either channel.
Stores outgrowing a marketplace connector app
You're on a connector app that treats Amazon FBA inventory as a separate pool from Shopify, and stock counts keep drifting out of sync.
Multi-SKU catalogs with variant complexity
Your product variants and SKUs don't map cleanly between Shopify and Amazon's listing structure, and manual matching is error-prone.
Businesses that need returns and cancellations synced
An Amazon return or cancellation doesn't reliably update your Shopify inventory or order status, creating blind spots for your team.
Sellers evaluating custom build vs off-the-shelf
You're not sure whether your setup is simple enough for a connector app or complex enough to need something custom.
Not a fit for
You need to sync eBay or Etsy specifically rather than Amazon. We build dedicated integrations for those marketplaces too, each around that platform's own API.
You're only running a handful of SKUs on Amazon with no FBA involved. A standard marketplace connector app will likely cover that without custom development.
You need your outsourced 3PL warehouse synced rather than a marketplace channel. Our Shopify 3PL Integration service covers that.
You're not on Shopify. This integration is Shopify-specific, and other platforms would need to be scoped separately.
11The Right Technology for Your Project
Technology Stack
We integrate through Amazon's Selling Partner API and Shopify's own APIs, matched to your FBA and FBM mix.
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12FAQ
Frequently Asked Questions
Straight answers on Shopify Amazon integration, FBA vs FBM, and overselling prevention.
How does inventory sync between Shopify and Amazon work?
Amazon's Selling Partner API and Shopify's Admin API both expose inventory endpoints, and the integration keeps available stock in sync by pushing count changes from whichever platform sold first, with a short buffer built in to cover each API's own sync delay so neither side oversells.
How are Amazon orders pulled into Shopify?
The integration polls or subscribes to Amazon's Orders API and creates a matching order in Shopify with the customer, line items, and fulfillment status, so your team can manage Amazon and Shopify orders from one place.
Can you handle FBA and FBM together?
Yes. We build routing rules that treat FBA and FBM as separate inventory pools with their own buffer stock, so an FBA sale doesn't oversell your FBM stock and vice versa.
How do you prevent overselling across Shopify and Amazon?
We set buffer stock per SKU that accounts for the sync delay between platforms, and route fulfillment based on your FBA/FBM split, so the count Amazon and Shopify show stays conservative enough to avoid a sale you can't fulfill.
How much does a custom Shopify Amazon integration cost?
Projects typically start from $1,999 for a single-marketplace, standard catalog integration, and scale up with FBA and FBM combined, high SKU counts, or multiple Amazon marketplaces. You get a fixed quote after reviewing your catalog and fulfillment mix.
Can you map product listings and variants automatically?
Yes, when SKUs are consistent between platforms. Where they aren't, we build a matching step during setup so Shopify variants map to the correct Amazon listing before the sync goes live.
How are returns and cancellations synced?
Amazon return and cancellation events from the Orders API trigger an update to the matching Shopify order and restock the inventory, so a returned item doesn't sit as sold on your Shopify count.
When does a custom build beat an off-the-shelf connector?
An off-the-shelf connector usually works fine for a single fulfillment method and a modest SKU count. A custom build makes sense once you're running FBA and FBM together, need buffer stock tuned per SKU, or a connector app's fixed sync schedule is costing you oversold orders.