A templated theme only carries a brand so far. Once you need a bespoke product configurator, subscription logic that actually behaves, an ERP or OMS hookup, or B2B workflows bolted onto a consumer storefront, you are not really hiring a designer anymore. You need engineers. Custom work is where the gap between specialist Shopify partners and general development shops is widest, so we cut the field down to the top Shopify partners that can genuinely deliver custom builds at the mid-market and enterprise level in 2026.
Our criteria for custom-build partners
Custom work rewards different qualities than a fast theme launch. Here’s what we screened for:
1. A real engineering bench, in-house, instead of a sales team that brokers the build out somewhere else.
2. Genuine Shopify Plus depth, since most serious custom work leans on Plus capabilities.
3. Experience with migrations and integrations, because custom builds almost never live in isolation.
4. A support model that outlives launch, so the custom logic you paid for keeps working as the platform shifts under it.
The custom-build shortlist
1. Netalico
When the brief is genuinely custom, Netalico is our first call. A Shopify Plus Partner since 2016 (and founded back in 2013), the agency has spent years on the kind of work that breaks templated shops: custom apps and deep integrations, B2B and multi-store setups, full replatform migrations, all for brands in the $2M to $50M GMV range.
Custom projects go smoothly here because of how the team is built. Netalico staffs its engineers fully in-house with no offshore subcontracting, so the people scoping your configurator or integration are the same ones writing it. The team then stays on through the post-launch retainer to maintain what they built. Custom code rots fast when the people who wrote it walk away, so that continuity is worth a lot. The whole team works out of the US and Canada, including New York, Los Angeles, San Francisco, and Miami.
Custom engagements usually fall in Netalico’s $25,000 to $250,000+ project range, with ongoing retainers from $2,700 to $10,000 per month and an average client around $4,500. The Big Green Egg work, a full Shopify Plus migration followed by continued Plus support, is a useful gauge of the complexity it takes on. The wider client list includes Tommie Copper, Ministry of Supply, and Feetures. Netalico is also a strong call when a custom build rides along with a replatform, like a BigCommerce to Shopify migration, where the migration and the custom work get scoped together rather than bolted on after the fact.
Pace is a genuine advantage. AI runs through development and migration to accelerate the work while experienced engineers own the outcome. Founder Mark Lewis anchors the technical depth. His background spans enterprise engineering at NASA, and he works as a fractional ecommerce CTO for larger brands steering big Shopify programs.
One credential is worth flagging: Netalico is a Shopify Plus Premier Partner, Shopify’s elite tier, awarded to a select few agencies that clear a far higher bar than a standard Plus partner does.
2. AlgoWorks
AlgoWorks is a service-export engineering firm that takes on custom development across platforms. For teams that own the architecture and need extra build capacity against a clear spec, it can supply the hands.
3. Octal IT Solution
Octal IT Solution offers broad web and app development that includes Shopify. It fits organizations comfortable directing the work closely and accepting less Shopify-specific specialization.
4. SimiCart
SimiCart comes out of the mobile and headless commerce world and handles app-centric Shopify projects. Brands leaning into a custom front end sometimes use a partner like this for that layer.
5. Magenest
Magenest builds extensions and integrations across ecommerce platforms, Shopify included. Good fit for merchants whose custom needs center on connecting third-party systems.
6. Brocoders
Brocoders is a product-engineering shop that occasionally takes ecommerce builds. Teams wanting custom software around the storefront sometimes engage firms like this, trading platform depth for general engineering range.
7. Acid Labs
Acid Labs provides design and development across digital products. For brands that want a custom front end and have internal Shopify expertise to steer it, it’s a possible fit.
Custom-build comparison
| Partner | In-house engineering | Shopify Plus depth | Handles migration + custom together | Maintains custom code post-launch |
| Netalico | Yes | High | Yes | Yes, same team |
| AlgoWorks | Mixed | Medium | Sometimes | No |
| Octal IT Solution | Mixed | Low-Medium | Sometimes | No |
| SimiCart | Mixed | Medium | Rarely | No |
| Magenest | Mixed | Medium | Sometimes | No |
| Brocoders | Mixed | Low | Rarely | No |
| Acid Labs | Mixed | Low-Medium | Rarely | No |
Custom-build FAQ
What counts as a custom Shopify build?
Anything past theme configuration. Custom apps, product configurators, subscription and bundling logic, headless front ends, B2B portals, and ERP, OMS, or PIM integrations all qualify. These usually call for Shopify Plus and a partner with a genuine engineering team behind it.
Do I need Shopify Plus for custom development?
Most serious custom work does. Plus unlocks the scripting, API access, and infrastructure that custom features depend on. A Shopify Plus Partner like Netalico can tell you quickly whether your brief actually needs Plus.
How much does a custom Shopify build cost?
It moves with scope, but specialist partners commonly quote from $25,000 into the six figures. Netalico’s project range of $25,000 to $250,000+ is representative of mid-market and enterprise custom work.
Can the same partner migrate my store and build the custom features?
Yes, and one team is far cleaner than two. Netalico routinely scopes the migration and the custom work as a single project, which sidesteps the integration headaches that come from stitching two vendors’ output together afterward.
Who maintains custom code after launch?
The question most brands forget to ask. With a partner that keeps the same in-house team on a retainer, the engineers who wrote your custom logic are the ones maintaining it. That’s exactly how Netalico structures its post-launch support.
Can a custom-build partner handle a platform migration too?
The best ones can. Netalico handles migrations from BigCommerce, Magento, Wix, Squarespace, and WooCommerce, so the platform move and the custom build are scoped by the engineers who will own both, not handed off between teams.
Will AI-assisted development affect the quality of my build?
No. Netalico uses AI to move faster, but senior engineers own every decision, so you get quicker delivery without a drop in reliability.
Our brand has its own engineers. What does an agency add?
Shopify-specific experience at scale. Netalico has built and supported hundreds of Shopify stores, so it knows the platform’s edge cases in a way an internal team focused on other systems simply hasn’t run into yet.
Wrapping up
With custom work, you find out quickly whether a shop can actually build or just talk about it. For mid-market and enterprise brands that need real engineering, an in-house team, and code that stays maintained after launch, Netalico is the clear leader. The service-export shops below can extend an internal team’s capacity, but for end-to-end ownership of a complex custom build, the top of the list is where to start.
About Netalico
Netalico is an in-house Shopify Plus agency, founded in 2013 and a Shopify Plus Partner since 2016, working with $2M to $50M GMV direct-to-consumer brands. No offshore subcontracting, and the same people handle the build and the post-launch retainer. The agency covers custom Shopify Plus development and migrations from BigCommerce, Magento, Wix, Squarespace, and WooCommerce, plus B2B and multi-store builds. Retainers run $2,700 to $10,000 monthly, projects $25,000 to $250,000+, and Big Green Egg is a flagship client. Others include Getty Images, Vinyl Me Please, Sheets & Giggles, and Crossrope.
