Custom e-commerce development for U.S. brands that have outgrown the template.
When your business logic outpaces what a theme or plugin can handle, you need an engineering team that writes code, not one that configures settings. We build custom e-commerce platforms, headless storefronts, and AI-powered commerce experiences for D2C brands, retailers, startups, and the agencies that serve them.
Custom e-commerce development for U.S. brands that have outgrown the template. We build custom platforms, headless storefronts, and AI-powered commerce experiences for D2C brands, retailers, startups, and the agencies that serve them.
You'll hear from an engineer within one US business day.
25 +Years
Engineering enterprise software
600 +Clients
Across 20+ countries
100 +
Custom e-commerce platforms delivered
CMMI L5
Certified delivery process
Trusted by U.S. brands, retailers, and technology organizations
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Three points where commercial platforms stop solving your problem, and where custom engineering picks it up.
Shopify, Magento, and BigCommerce are built for the average store. Once your pricing logic, catalog structure, or checkout workflow stops being average, the platform enforces its own constraints. You spend development cycles working around them instead of building toward your roadmap. Custom engineering removes the ceiling.0
When ERP, CRM, PIM, OMS, and payment data don’t move cleanly between systems, the gap fills with manual reconciliation, duplicate records, and errors that compound at scale. A properly engineered integration layer solves this once. Not with a workaround that needs maintenance every six months.
Client deadlines don’t flex because your dev bench isn’t deep enough. Digital agencies and software companies bring us the e-commerce builds that need engineering depth they don’t have in-house. We work white-label, stay invisible, and ship on your timeline, not ours.
Whether you need a platform built from scratch or a team that extends yours, our services are built around your outcomes, not deliverable checklists.
Custom-built online stores and B2C, B2B, and D2C commerce platforms designed around how your business actually operates.
Large-scale commerce for retailers and B2B sellers: high-SKU catalogs, account-based pricing, bulk ordering, and omnichannel operations built to hold enterprise volume without performance compromise.
API-first storefronts on Next.js, React, and the MERN stack, decoupled from the backend so your team can ship experiences without waiting on a platform’s release cycle.
A dedicated engineering team that plugs into your sprint cadence, code reviews, and staging environments, so working with an external team feels like extending your own.
Native iOS and Android shopping apps and mobile commerce experiences built for D2C brands and retailers that need mobile to convert, not just exist.
AI-generated code is changing how e-commerce platforms are built. AI-driven features are changing what customers expect from them. We engineer both.
We integrate AI capabilities into custom e-commerce builds from the architecture phase. From personalization engines and conversational commerce to demand forecasting and AI-powered search, our AI engineering team treats intelligence as a core system, not a feature bolt-on.
Talk to Our AI Commerce TeamReal projects. Confirmed outcomes.
Restaurant Operations Hub
Multi-service restaurant management platform with live orders, inventory, and automated payments.
Event Ticketing Platform
Multi-market event ticketing with payments, digital tickets, and analytics.
Real Estate Auctions
Enterprise asset auction platform with live bidding and payment automation.
Marketplace & Auctions
C2C marketplace with auctions, location discovery, and secure payments.
Uniform Customization Tool
Web-based uniform personalisation for sports teams and businesses.
Virtual Try-On
AR-powered virtual try-on with AI body mapping for apparel.
The difference between a platform built to hold up under your business and a platform built to look good in the demo.
You own 100% of the code from sprint one
No licensing holdbacks. No component ownership clauses. No “we need to unpick our modules if you leave.” Your source code, your architecture, and your IP — governed by California law from our US entity. Your contracts are yours from the first line of code.
We write what the platform can’t
When Shopify Plus, Adobe Commerce, or BigCommerce limits your pricing, checkout, or catalog, we write custom code to overcome it. Not fragile workarounds, but real engineering that removes the constraint permanently.
CMMI Level 5 process on every build, not just contracts
The same delivery process that governs our largest enterprise engagements runs on every project we take on, regardless of size. Sprint cadence, QA gates, deployment pipelines, and escalation paths are documented from kickoff. Not improvised as the build progresses.
US entity. US business hours. US-law contracts.
Our Emeryville, CA office provides legal, operational, and contractual US presence. Your account lead works US hours. Sprint reviews occur in your time zone. Escalation connects to a named individual with a direct number. We engineer out communication delays.
Seasia helped us bring several complex vendor workflows into one platform without making the experience difficult for merchants. The team handled real-time orders, payouts, permissions, and integrations well while staying responsive as the product continued to evolve.
The team understood that ticketing was only one part of the platform. They helped us build around payments, refunds, organizer workflows, subscriptions, and reporting, while keeping the experience reliable for both event organizers and customers across different markets.
Seasia handled the real-time auction requirements with a strong understanding of how sensitive bidding workflows can be. The platform brought together online bidders, floor activity, live streaming, payments, and automated auction states in a much more controlled way.
What stood out was the team's ability to support multiple marketplace models within one ecosystem. Buy, sell, trade, auctions, location-based discovery, chat, and payments all had different workflows, but the final experience felt connected and easy to manage.
Seasia translated a highly visual customization process into a practical online experience. Users could personalize uniforms, preview their selections, and move directly into ordering, which made the journey much smoother for both customers and our internal team.
The virtual try-on experience gave us a more engaging way to help customers evaluate products online. Seasia brought together the front-end experience, visual technology, and shopping flow in a way that felt practical rather than gimmicky.
The questions U.S. e-commerce brands, retailers, startups, and agencies ask most often.
A production-ready custom B2C or D2C commerce platform typically starts between $25,000 and $75,000, depending on the number of integrations, checkout complexity, and whether a mobile app is included. Enterprise B2B platforms with ERP integration, account-based pricing engines, and approval workflows typically start higher.
Both. We extend Shopify Plus, Adobe Commerce, and BigCommerce well beyond their defaults using custom app development, checkout extensions, and API integrations. When the platform genuinely can’t support the business requirement, we recommend a custom build or a headless architecture.
Yes. Next.js, React, and the MERN stack are core to how we build headless and composable storefronts. We’ve built headless frontends decoupled from Shopify, Magento, and custom backends, giving teams full frontend independence and performance control without rebuilding the commerce logic underneath.
Yes. We integrate AI capabilities — personalization engines, product recommendation models, conversational commerce flows, demand forecasting, and AI-powered search — into existing platforms and custom builds. AI features we add are built to the same code quality and integration standards as the rest of the platform.
Our US entity in Emeryville, CA means your account lead operates on US business hours. Sprint reviews are live. The same engineers who scoped your project build it through to handover. Escalation connects to named individuals with direct contact details. We cannot promise we’ll never hit a technical problem. We can promise communication delays won’t be one.
Schedule 30 minutes with a senior commerce engineer. We’ll review your platform constraints, integration requirements, and growth goals, and give you a straight answer on what the right architecture is.
No pitch deck. No handoff to sales. Just an engineer.
You'll hear back from an engineer within one business day.
