Every growing retailer eventually hits the same wall: the platform that got you to your first million in GMV starts fighting you past your fifth. The question isn't "which platform is best" — it's which architecture matches your GMV, your roadmap, and how much control you actually need over checkout, content, and integrations. This guide gives you a structured way to answer that, plus the specific questions to ask before you commit budget.

Who this is for

Ecommerce leaders and IT decision-makers evaluating a replatform or rebuild — typically triggered by a growth plateau, a checkout limitation, slow page speed, or an ERP/CRM integration that's outgrown the platform's native capabilities.

Step 1: Know where you actually stand

  • [ ] Annual GMV — under $1M, $1M–$5M, $5M–$10M, or $10M+? This single number eliminates more options than any feature comparison.
  • [ ] Checkout customization needs — do you need subscription logic, complex tax rules, B2B pricing tiers, or multi-entity checkout that your current platform's checkout API can't handle?
  • [ ] Content and merchandising velocity — how often does marketing need to ship new landing pages, campaigns, or storefront experiments without an engineering ticket?
  • [ ] Existing integration debt — how many systems (ERP, CRM, PIM, loyalty, tax engine) currently talk to your storefront, and how brittle are those connections?
  • [ ] Internal engineering capacity — do you have (or are you willing to hire) a team that can own a custom frontend and its uptime?
  • [ ] International/multi-brand complexity — multiple storefronts, currencies, or regional catalogs from one backend?

Step 2: Match your profile to an architecture

Choose Shopify Plus (or an equivalent managed platform) if:

  • GMV is roughly $1M–$5M and growing but not yet at a scale where platform fees outweigh a custom build's cost.
  • You need moderate checkout customization (Shopify's Checkout Extensibility API covers most of it) without owning the underlying commerce engine.
  • You want dedicated merchant support and a faster time-to-market than a custom build allows.
  • Your content/merchandising needs are served fine by themes and apps.

Choose headless commerce if:

  • A themed storefront genuinely can't do the job — not "would be nicer," but a real blocker: independent channel experiences (app, kiosk, marketplace), frequent frontend experimentation, complex subscription logic, or multiple payment paths across regions.
  • Page speed and Core Web Vitals are a competitive factor in your category (cached headless pages can serve in well under 100ms vs. 300–800ms for typical themed pages).
  • You're expanding into multiple markets or brands from a shared commerce backend and need independent frontends per market.
  • You have the engineering capacity to own a decoupled frontend (Next.js/Nuxt or similar) plus its hosting, monitoring, and release process.

Choose a fully custom build if:

  • GMV exceeds roughly $10M and platform + transaction fees on a managed plan now exceed the annualized cost of ownership.
  • Your business logic (pricing, inventory allocation, fulfillment routing, loyalty) is a genuine differentiator that off-the-shelf platforms force you to work around.
  • You need 100% IP ownership and zero vendor lock-in as a strategic requirement, not a preference.
  • You're prepared for a longer build timeline in exchange for exact workflow fit and no per-seat or GMV-based licensing ceiling.

Step 3: Questions to ask any vendor or internal team before you commit

  1. What is the fully loaded first-year cost — platform/license fees, build cost, hosting, and ongoing maintenance — not just the sticker price?
  2. What happens to page performance and SEO rankings during and immediately after migration?
  3. Who owns uptime and incident response after launch — the vendor, an agency, or your internal team?
  4. How does the proposed architecture handle your specific ERP, CRM, and tax-engine integrations today, not hypothetically?
  5. What's the realistic timeline to first production release, and what's the cost of slippage?
  6. If you choose headless, which parts of the "backend" (inventory, promotions, subscriptions) still live on the commerce platform vs. custom services?
  7. What's the exit path if this platform stops fitting in three years — how portable is your data and business logic?

Red flags to watch for

  • [ ] A vendor who can't give you a real number for ongoing maintenance cost, only the build estimate.
  • [ ] A headless proposal with no plan for who maintains the frontend after launch.
  • [ ] A custom-build pitch that ignores your existing ERP/CRM integration complexity.
  • [ ] Any estimate that doesn't account for SEO migration risk if you're replatforming an existing storefront.

How to use this

Score your business against Step 1 first — most of the decision falls out of GMV and checkout complexity alone. Use Step 3's questions verbatim in vendor conversations; a vendor who can't answer them clearly is a signal, not just a data point. If you're already leaning toward headless, pair this with our headless commerce vendor evaluation scorecard before you shortlist partners.