--- title: "Custom Shopify Plus Development | Mejix" url: https://www.mejixshop.com/services/shopify-plus-development description: "Custom Shopify Plus design and development by a certified Plus Tier partner — bespoke themes, performance, and conversion-led UX." lang: en --- Request a Strategy Call: https://www.mejix.com/contact/ Service · Development # Custom Shopify Plus Design & Development High-converting Shopify Plus storefronts built for performance, scale, and brand expression — engineered by a certified Plus Tier partner. Request a Strategy Call: https://www.mejix.com/contact/ See related case studies: https://www.mejixshop.com/case-studies Image: Layered translucent storefront panels representing custom Shopify Plus development (https://www.mejixshop.com/assets/development-hero-KLOP1XIV.jpg) What it is ## About this Shopify Plus service Custom Shopify Plus development is the work of turning a brand into a fast, scalable, conversion-tuned commerce experience on Shopify's enterprise platform. It goes far beyond installing a theme — it covers information architecture, custom components, performance budgets, accessibility, and the integrations your business actually depends on. Mejix builds bespoke Shopify Plus storefronts for high-growth brands across B2B, fashion, health & beauty, jewelry, and large-catalog retail. Every project starts with the merchandising, content, and operational reality of your business — not a template. The output is a storefront that loads fast, ranks well, and converts the traffic you already pay for. Because we're a Plus Tier partner active since 2022, we know which Shopify Plus features (Checkout Extensibility, B2B, Markets, Functions, metafields, metaobjects) are worth leveraging and which are noise. The result is less custom code, less risk, and a storefront that's easier to evolve over the next three years. What's included ## Concrete deliverables Every engagement ships a defined scope. No vague promises — these are the artifacts and outcomes you can expect. ### Custom theme & components Bespoke Liquid theme with reusable section components, metaobject-driven content, and a clean editor experience for marketers. ### Performance engineering Real-world Core Web Vitals targets, image and font budgets, third-party script audits, and Shopify CDN-first delivery. ### Mobile-first responsive UX Designed for the device most of your revenue comes from. Touch targets, sticky carts, and one-thumb navigation patterns. ### Storefront engineering Custom sections, blocks, app blocks, and Functions where they earn their keep. No bloat, no abandoned third-party apps. ### Accessibility & quality WCAG 2.1 AA targets, semantic HTML, keyboard support, and automated regression testing baked into the build. ### Handover & enablement Documentation, recorded walkthroughs, and a clean Shop OS your in-house team can own without us in the loop. How it works ## A predictable delivery process The same sequence we run on every engagement, refined across enterprise Shopify Plus projects. 1. 01 ### Discovery & scoping We map your catalog, merchandising rules, integrations, and brand language. Output: a written scope with assumptions and risks. 2. 02 ### Design & architecture Wireframes, design system tokens, and theme architecture mapped to metafields and metaobjects so content owners stay independent. 3. 03 ### Build & integrate Iterative weekly builds with a staging environment, integration tests, and content migration scripts. 4. 04 ### QA, launch & hypercare Cross-browser, accessibility, Lighthouse, and integration QA, then a controlled cutover with on-call hypercare for the first two weeks. Why Mejix ## A certified Plus Tier partner We don't sell what we haven't shipped. Every credential below is verifiable on the Shopify Partner Directory. ### Shopify Plus Partner — Plus Tier Verified on the official Shopify Partner Directory. Active partner since August 2022. ### 12+ countries served Brands in the US, UK, Israel, and across Europe — many running internationally on a single Shopify Plus stack. ### Real enterprise work 50,000-SKU migrations, custom payment gateways, PIM integrations — not just landing pages. How To ## How to: Custom Shopify Plus Design & Development Practical answers to the most common 'how do I…' questions teams ask before starting. ### How do I scope a custom Shopify Plus build? ### How do I keep a custom theme maintainable? ### How do I hit Core Web Vitals on Shopify Plus? ### How do I migrate content without breaking SEO? ## Frequently Asked Questions ### Do I need Shopify Plus to use Mejix? ### How long does a custom Shopify Plus build take? ### Can you work with our existing design team? ### Do you provide ongoing support after launch? ### Do you build headless storefronts? Go deeper ## Related services & resources Useful next stops — sibling services on this site and verified pages on mejix.com. ### On this site - Headless Commerce Development: https://www.mejixshop.com/services/headless-commerce - Conversion Rate Optimization: https://www.mejixshop.com/services/shopify-plus-cro - Checkout Extensibility & Scripts: https://www.mejixshop.com/services/checkout-extensibility - All Shopify Plus services: https://www.mejixshop.com/services - The Migration Playbook: https://www.mejixshop.com/shopify-plus-migration-playbook ### On mejix.com - Mejix Services overview: https://www.mejix.com/services/ - About Mejix: https://www.mejix.com/about/ - Talk to the team: https://www.mejix.com/contact/ - Shopify Partner Directory listing: https://www.shopify.com/partners/directory/partner/mejix-inc ## Ready to scope your Development project? We'll review your goals and propose a roadmap — no obligation. Request a Strategy Call (https://www.mejix.com/contact/) ## Structured data ```json [ { "@context": "https://schema.org", "@type": [ "Organization", "ProfessionalService" ], "@id": "https://www.mejixshop.com/#organization", "name": "Mejix Inc.", "alternateName": "Mejix", "url": "https://www.mejixshop.com", "logo": "https://www.mejixshop.com/favicon.svg", "image": "https://www.mejixshop.com/images/mejix-social.png", "description": "Shopify Plus Partner (Plus Tier) engineering enterprise commerce: migrations, ERP integrations, Checkout Extensibility and headless builds.", "email": "hello@mejix.com", "telephone": "+1-212-401-6213", "priceRange": "$$$$", "foundingDate": "2022-08", "sameAs": [ "https://www.shopify.com/partners/directory/partner/mejix-inc", "https://www.linkedin.com/company/mejix", "https://www.mejix.com" ], "address": [ { "@type": "PostalAddress", "addressLocality": "New York", "addressRegion": "NY", "addressCountry": "US" }, { "@type": "PostalAddress", "addressLocality": "Cluj-Napoca", "addressCountry": "RO" } ], "areaServed": [ "US", "CA", "GB", "EU", "IL" ], "knowsLanguage": [ "en", "fr", "he" ], "knowsAbout": [ "Shopify Plus", "Shopify Plus Migration", "Checkout Extensibility", "Headless Commerce", "Shopify Hydrogen", "ERP Integration", "NetSuite", "PIM Integration", "Shopify Flow", "Conversion Rate Optimization", "B2B eCommerce" ], "memberOf": { "@type": "Organization", "name": "Shopify Partner Program (Plus Tier)", "url": "https://www.shopify.com/partners/directory/partner/mejix-inc" } }, { "@context": "https://schema.org", "@graph": [ { "@type": "Service", "name": "Custom Shopify Plus Design & Development", "description": "Custom Shopify Plus design and development by a certified Plus Tier partner — bespoke themes, performance, and conversion-led UX.", "serviceType": "Custom Shopify Plus Design & Development", "provider": { "@type": "Organization", "name": "Mejix", "url": "https://www.mejix.com" }, "areaServed": "Worldwide", "url": "https://www.mejixshop.com/services/shopify-plus-development" }, { "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://www.mejixshop.com/" }, { "@type": "ListItem", "position": 2, "name": "Services", "item": "https://www.mejixshop.com/services" }, { "@type": "ListItem", "position": 3, "name": "Custom Shopify Plus Design & Development", "item": "https://www.mejixshop.com/services/shopify-plus-development" } ] } ] }, { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "How do I scope a custom Shopify Plus build?", "acceptedAnswer": { "@type": "Answer", "text": "Start by mapping the merchandising, content, and integration realities of your business before talking about visual design." } }, { "@type": "Question", "name": "How do I keep a custom theme maintainable?", "acceptedAnswer": { "@type": "Answer", "text": "Lean on Shopify-native primitives — sections, blocks, metafields, metaobjects, and app blocks — instead of hand-rolled custom code. Custom JavaScript should be the exception, not the default." } }, { "@type": "Question", "name": "How do I hit Core Web Vitals on Shopify Plus?", "acceptedAnswer": { "@type": "Answer", "text": "Budget images and fonts, defer non-critical JS, lazy-load below the fold, prefer Shopify's CDN over external hosts, and measure real user metrics — not just lab scores." } }, { "@type": "Question", "name": "How do I migrate content without breaking SEO?", "acceptedAnswer": { "@type": "Answer", "text": "Preserve URL structures wherever possible, build a complete 301 redirect map, validate it in staging, and submit a fresh sitemap on launch." } } ], "url": "https://www.mejixshop.com/services/shopify-plus-development" }, { "@context": "https://schema.org", "@type": "HowTo", "name": "How do I scope a custom Shopify Plus build?", "step": [ { "@type": "HowToStep", "position": 1, "text": "List every product type, variant rule, and merchandising surface you sell from today." }, { "@type": "HowToStep", "position": 2, "text": "List every external system the storefront must read from or write to (ERP, PIM, OMS, ESP, CDP, custom payments)." }, { "@type": "HowToStep", "position": 3, "text": "Decide which content is owned by marketers (sections, metaobjects) versus engineers (theme code)." }, { "@type": "HowToStep", "position": 4, "text": "Set explicit performance and accessibility targets up front — they shape every later decision." }, { "@type": "HowToStep", "position": 5, "text": "Translate the above into a written scope, with assumptions and risks, before any design starts." } ] }, { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "Do I need Shopify Plus to use Mejix?", "acceptedAnswer": { "@type": "Answer", "text": "Most of our engagements are on Shopify Plus, but we also work with growing brands on the standard plan that have a clear path to Plus within 12 months." } }, { "@type": "Question", "name": "How long does a custom Shopify Plus build take?", "acceptedAnswer": { "@type": "Answer", "text": "Most builds run 10–16 weeks from kickoff to launch, depending on catalog complexity, integrations, and content migration scope." } }, { "@type": "Question", "name": "Can you work with our existing design team?", "acceptedAnswer": { "@type": "Answer", "text": "Yes. 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