21phi builds and runs Shopify Plus storefronts on Hydrogen, then stays embedded with your team as the people who close every request, from checkout logic to a broken app.
21phi is a Shopify Plus development agency that designs, builds and runs storefronts for brands that have outgrown their current stack. It is for direct-to-consumer brands on Shopify Plus, or moving to it, that want a faster store, custom logic in the cart and at checkout, and one senior team that stays on after launch.
Shopify Plus is Shopify's enterprise plan with higher limits, checkout extensibility, Shopify Functions, B2B and Markets features. Most brands arrive on it with a Liquid theme carrying years of apps and workarounds. Plus gives you the tools to replace them with real logic, and using those tools well is development work.
We are a small senior team, a Shopify Partner with Shopify Plus experience, based in Toronto and working with brands across the United States and Canada. Sergey Gridin, co-founder, leads the engineering work with clients. What sets us apart from most Shopify Plus development companies is what happens after launch: we stay as your embedded team and close any request from any department, integrations, visuals, broken apps, urgent fixes, analytics. This costs more than a body shop, and we think it should.
Brands come to us when the theme has become the ceiling. The catalog has rules the theme editor cannot express, the cart needs pricing logic an app only half delivers, or the store sells in two countries with one price list. Shopify Plus removes the platform ceiling. Development removes the rest.
We also tell you when it is not the right move. If a well-built theme covers the experience, we say so on the first call. Shopify's hosted checkout has limits on fonts, branding and sharing across storefronts, and we explain them before you commit.
If you are weighing whether to migrate to Shopify Plus, or planning a Shopify Plus migration from another platform, start with our Shopify migration services.
Our Shopify Plus development runs on Shopify Hydrogen, Shopify's React-based framework for building headless storefronts on top of Shopify's Storefront API; current versions are built on React Router (formerly Remix). Storefronts deploy to Oxygen, Shopify's global edge hosting for Hydrogen storefronts, included with Shopify plans; it deploys from Git. Headless means the storefront front end is decoupled from Shopify's back office and checkout and talks to Shopify through APIs; Shopify still runs products, orders, customers and checkout.
The commerce logic goes where Plus wants it. Shopify Functions are server-side custom logic Shopify runs at checkout and in the cart (discounts, cart transform, delivery and payment customisation), which is how cart and discount rules live in the platform rather than in a theme script. Checkout extensions are Shopify's supported way to customise checkout (UI extensions, branding API, Shopify Functions) without editing checkout.liquid; checkout itself stays Shopify-hosted. Shopify Markets, Shopify's multi-market tooling for pricing, currency, language and domains per country, carries locale-aware pricing and discount display for US and Canadian shoppers from one store.
We sit in your own channels. 21phi joins the group chats for web, customer care and the wider team, and questions from any teammate get answered there directly by the person who will do the work. A shared task board shows what is in progress and what shipped, with a weekly update.
Requests come from every department and all of them land with us. Customer care asks for a final-sale label or a fix to a discount code at checkout. Logistics asks why inventory is not syncing. Marketing needs a landing page for a drop. The founder wants the navigation changed. One team, one place to ask, and when something is not possible on the platform we say so and offer the nearest thing that is.
The real work on a Shopify Plus store starts after launch, and this is where we differ from a Shopify Plus development company that ships and leaves. Urgent fixes go to the front of the queue. When the support team asked for a chat widget, it was scoped, reviewed with the founder and shipped by the same people. When the reviews platform, the helpdesk chat or the inventory middleware misbehaves, 21phi chases the vendor. Framework, package and Shopify API version upkeep is a standing monthly item, so the storefront does not break.
This costs more than a body shop. A body shop bills for tickets and knows nothing about your store on Monday morning. An embedded team of Shopify Plus experts with a named senior engineer on the other end knows the codebase, the catalog rules, the ads calendar and the people who ask. That is why an urgent fix goes to the front of the queue instead of waiting for a sprint, and why the money you spend on Plus development keeps compounding instead of decaying.
If you are comparing one Shopify Plus agency with another, ask three things. Can they show a Plus store they still run, not just one they launched? Do they build on Plus features, checkout extensibility, Functions, Markets, or do they install apps and call it custom? And who, by name, answers when something breaks during a launch?
Our answers: one of our Shopify Plus clients, an apparel brand, runs on a Hydrogen storefront we built and continue to operate, with product systems, a custom cart, a multi-market setup and a store-credit wallet. We build on Plus features because that is what Plus is for. And Sergey Gridin leads the engineering work with clients.
We are a Shopify Plus design agency as much as a development one. Design systems and product page design come from the same senior people who write the storefront code. See Shopify Hydrogen development for the headless side and Shopify support and maintenance for how the retainer works.
A Shopify Hydrogen storefront for a men's performance apparel brand, built around product systems and run by 21phi as the embedded storefront, analytics and growth team.
Shopify Plus · Shopify Hydrogen on Remix / React Router · Oxygen edge hosting · Storefront API and Customer Account API · Shopify Markets · Shopify web pixels and ad pixels, implemented in code · Amplitude for funnels, retention and session replay · Mux for video
A Shopify Plus development agency builds and maintains storefronts on Shopify Plus, Shopify's enterprise plan. At 21phi that means a Hydrogen storefront on Oxygen, cart and checkout logic through Shopify Functions and checkout extensions, Shopify Markets for multi-country selling, custom integrations, and an embedded team that keeps running the store after launch rather than handing it back.
21phi is a Shopify Partner with Shopify Plus experience. We build on Shopify Plus features such as checkout extensibility, Shopify Functions and Shopify Markets, and we run a large Shopify Plus storefront for an apparel brand today. We also tell clients what Shopify's hosted checkout and app platforms cannot do before they commit, so the plan rests on what the platform supports.
Yes. A Shopify Plus headless build is our default: a Hydrogen storefront on Oxygen that talks to Shopify through the Storefront API and the Customer Account API, while Shopify keeps running products, orders, customers and checkout. Checkout stays Shopify-hosted and is customised through checkout extensibility, not replaced, so you keep Shopify's payment methods and checkout security.
Yes. 21phi plans and runs migrations to Shopify Plus from a standard Shopify plan and from a Liquid theme to a Hydrogen storefront, and applies the same method to replatforming from other ecommerce platforms. Migrations keep URL maps and redirects, metadata and structured data, with staged rollouts, test orders in each market and monitoring after the switch. Details are on our Shopify migration services page.
Yes. Shopify Plus work usually starts with a store that already trades. We start with a stack audit, then either take over the existing storefront or rebuild it on Hydrogen. Either way you get the same embedded team afterwards: a named senior engineer and requests from any department closed by people who know the codebase.
21phi designs, builds and keeps running headless storefronts on Hydrogen, Oxygen and the Storefront API for Shopify Plus brands, and stays embedded with your team as the people who own the store after launch.
21phi plans and runs Shopify migrations, from a Liquid theme to Hydrogen, from Shopify to Shopify Plus, or from another platform onto Shopify, and stays on as the team that runs the store afterwards.
The real work starts after launch.
