When Shopify and WooCommerce
both say no, we build the platform
A custom platform earns its cost the moment a store's pricing logic does not fit Shopify or WooCommerce. Same for a promo engine or checkout flow that needs fragile workarounds to work at all. We build these on Next.js and FastAPI, the same stack behind our own marketplace. Margin and stock guards get wired in from the first version, not bolted on after a bad order.
Where a platform’s rules run out
A custom e-commerce platform is the right call when the business model does not fit inside a platform’s rules. Pricing that varies by region, supplier or quantity in ways no promo app replicates cleanly. A checkout flow with steps a standard platform’s template does not support. A catalogue that needs logic a plugin would only approximate.
It is the wrong call for a standard catalogue on a normal timeline, where Shopify or WooCommerce gets a store live faster and cheaper. We recommend those first, and only propose custom when we can point to the specific rule that breaks on them.
What is inside
A backend owns the actual business logic: pricing, promo mechanics, stock and margin rules. None of it sits scattered across app settings nobody fully understands six months later. Checkout recalculates every price server-side instead of trusting whatever the client sent. Order creation is idempotent, so a retried request or a flaky connection never creates a duplicate charge.
Local payment and delivery integrations connect to the providers the target market actually uses. An admin panel is built for the team that will run the store day to day, with roles, so a warehouse staffer cannot edit pricing rules.
How we build it
We start by writing down the specific rule that does not fit a standard platform. That rule drives every architectural decision that follows. The data model gets designed around it first, then the checkout and payment flow, then the admin panel.
We build the margin guard and stock checks before the storefront’s visual polish. A store that looks good and loses money on every third order has the priorities backward. Every pricing and checkout path gets automated tests, and a dry run against realistic order data happens before anything goes live for a real customer.
What to watch
The biggest risk on a custom build is scope creep disguised as “just one more rule.” A pricing engine that starts simple accumulates special cases. A year later, nobody fully understands them. That is how a custom platform becomes harder to maintain than the platform it replaced. We push every genuinely new rule through the same review as the original scope, documented and tested, rather than letting it slip in as a quick patch.
The second risk is treating custom as an excuse to skip automated testing. The thinking is “we’ll catch it manually.” That works until a pricing bug ships on a Friday. Nobody notices until Monday’s numbers look wrong. Checkout and pricing paths get tests from the first version. That is where a mistake costs real money, not where testing is a checklist item.
The third trap is building for a theoretical future scale the business does not have yet. Over-engineering for ten million orders when the real near-term need is ten thousand helps nobody. We build for the scale you actually have, with a clear path to grow, not a system over-built for a future that may not arrive on schedule.
Timeline and price
| Option | Price | What it covers |
|---|---|---|
| MVP | from $8,000 | Core catalogue, checkout, one payment method, basic admin panel |
| Production | from $14,000 | Custom pricing and promo logic, local payments and delivery, full admin panel with roles, automated tests |
| Full control (handover-ready) | from $15,000 | Everything in Production plus full source walkthrough, architecture documentation, and a 90-day support window instead of 30 |
Running cost after launch depends on hosting and, where relevant, model usage, typically $20 to $150 a month for a project at this scale.
What you own at the end
You own the full repository, deployed on infrastructure under your own accounts, with the database, the admin panel and every integration credential in your name. There is no proprietary platform lock-in the way a SaaS storefront builder creates. The code is yours to extend with any team, ours or otherwise, going forward.
This is the same handover standard on every store or marketplace we build. The platform account, every payment and delivery credential, and the full order history stay in your name from the first day, not just after a dispute. A written handover document explains what each integration does and why. A future developer, ours or someone else’s, can pick up the system without reverse-engineering it from the code alone.
Related
See the development service page for our full build process. This pairs with Digital goods marketplace and Subscription commerce platform. For the engineering detail, see Headless commerce storefront and Order management system. For a real build, see Digital goods marketplace automation and Supplements store in the Balkans, sales x10.
Want this built for your business? Get in touch and we will scope it with a fixed price.
FAQ
How much does a custom e-commerce platform cost?
From $8,000 for a store with custom pricing or promo logic, local payments and an admin panel, 8 to 14 weeks. A platform with supplier integrations or multi-region pricing runs $15,000 to $25,000.
Why not just use Shopify or WooCommerce?
Both are the right answer most of the time, and we say so when they fit. A custom build earns its cost when pricing rules, a checkout flow or an integration genuinely does not fit either platform's model. That is when fragile workarounds start breaking on every update.
What is the stack?
FastAPI and PostgreSQL on the backend, Next.js on the frontend, Redis for caching and session state. The same combination behind our own digital goods marketplace.
Who owns the code?
You do. The repository is yours from the first commit, deployed on infrastructure in your name, with no dependency on an account only we control.
What happens if our needs grow past the first build?
The architecture is built to add features without a rewrite: new payment methods, new promo mechanics, a new storefront region. We scope additions the same way as the original build, with a fixed price agreed before work starts.