E-commerce Software Development

Custom e-commerce software development encompasses building online stores, marketplace platforms, B2B portals, and headless commerce architectures tailored to your business model. StepTo builds scalable, high-performance e-commerce systems for retail, B2B, and marketplace companies — from custom storefronts with Next.js to complex order management systems processing millions of transactions. Our Serbian engineering team delivers e-commerce solutions at 40–60% lower cost than equivalent Western European or US agencies.

E-commerce Solutions We Build

Custom storefront development: Bespoke React/Next.js storefronts with server-side rendering for optimal SEO and Core Web Vitals. Tailored product pages, search, filtering, and checkout flows designed for your specific product catalogue.
Headless commerce: Decoupled architecture connecting best-in-class commerce engines (Shopify Plus, Commercetools, BigCommerce) with custom frontends. Deliver faster pages and greater flexibility than monolithic platforms.
Marketplace platforms: Multi-vendor marketplace systems with seller onboarding, commission management, dispute resolution, and split payment processing. Scalable from dozens to thousands of sellers.
B2B e-commerce portals: Customer-specific pricing, quote requests, purchase order workflows, account management, and integration with ERP systems for B2B manufacturers and distributors.
Order management systems (OMS): Custom OMS for omnichannel retailers managing orders across web, mobile, in-store, and third-party marketplaces. Inventory allocation, fulfillment routing, and returns processing.
Progressive web apps (PWA): Offline-capable, installable e-commerce PWAs with native-like performance on mobile. Significant conversion improvements for mobile-heavy audiences.
E-commerce integrations: API integrations with payment gateways (Stripe, Adyen, Klarna), shipping carriers (DHL, UPS, FedEx), ERP systems, and fulfilment centres.

Technology Stack for E-commerce

Frontend: Next.js, React, TypeScript, Tailwind CSS — for fast, SEO-optimised storefronts
Backend: Node.js (NestJS), Python (FastAPI), PostgreSQL, Redis — for scalable APIs and real-time inventory
Commerce platforms: Shopify Plus (custom apps & themes), Commercetools, BigCommerce, WooCommerce, Magento 2
Search: Algolia, Elasticsearch, Typesense — for fast product search with faceted filtering
Payments: Stripe, Adyen, PayPal, Klarna, Mollie, Stripe Connect (marketplace payments)
Infrastructure: AWS (CloudFront, ECS, RDS), Vercel, Docker, Kubernetes — for auto-scaling and global delivery

Why StepTo for E-commerce Development?

Proven track record: We rebuilt an e-commerce platform for a UK retailer — Lighthouse score improved from 32 to 91, checkout abandonment dropped 22%. See our case study.
Performance-first approach: E-commerce conversions depend on speed. We build with Core Web Vitals (LCP <2.5s, CLS <0.1, INP <200ms) as first-class requirements, not afterthoughts.
Cost efficiency: Senior e-commerce engineers from Serbia cost $35–65/hr versus $90–180/hr in Germany or the US — 40–60% savings on projects that typically run 3–12 months.
Full-stack capability: We handle everything from UX design and frontend development to backend APIs, DevOps, and ongoing support — no coordination overhead between multiple agencies.
CET timezone: Working hours overlap with both European and US East Coast business hours, enabling daily standups and same-day response for European e-commerce companies.

E-commerce Development Process

Discovery: Business model analysis, competitor benchmarking, UX research, and technical requirements definition (1–2 weeks)
Architecture & Design: System design, database schema, API contracts, wireframes, and visual design (2–4 weeks)
Core Development: Agile 2-week sprints delivering product catalogue, cart, checkout, and user accounts first
Integrations: Payment gateway, shipping, ERP, analytics, and marketing tool integrations
Performance Optimisation: Core Web Vitals tuning, image optimisation, caching strategy, and CDN configuration
Launch & Monitoring: Staged rollout, A/B testing setup, conversion funnel analytics, and error monitoring
Ongoing development: Feature additions, A/B tests, performance improvements, and platform upgrades

FAQ: E-commerce Software Development

How much does custom e-commerce development cost?: A custom e-commerce storefront typically costs $40,000–$150,000 depending on complexity, number of integrations, and feature scope. A full marketplace platform with multi-vendor support ranges from $100,000–$400,000. Working with StepTo's Serbian team saves 40–60% compared to equivalent UK, German, or US agencies for the same quality of output.
Should I use Shopify or build a custom platform?: For most merchants, Shopify or Shopify Plus is the right starting point — faster to market, lower maintenance overhead, and a mature ecosystem of apps. Custom development makes sense when you have unique business logic (complex B2B workflows, multi-currency marketplace, industry-specific compliance requirements) that Shopify's architecture can't support cost-effectively. We build both and can advise based on your specific requirements.
What is headless commerce and when should I use it?: Headless commerce separates the frontend (what customers see) from the backend commerce engine (inventory, orders, payments). This allows faster, more flexible frontends built with React/Next.js while retaining a battle-tested commerce backend. It's ideal for companies with heavy traffic, strong mobile audiences, or multi-channel presence (web + app + in-store). The trade-off is higher development cost and complexity versus monolithic platforms.
How do you handle payment processing and security?: We integrate with PCI-DSS compliant payment processors (Stripe, Adyen, Mollie) that handle card data directly — your servers never store sensitive payment information. We implement 3D Secure 2.0 for SCA compliance (required in Europe), fraud detection, and payment method optimisation per market. For marketplaces, we implement Stripe Connect or Adyen for Platforms to handle split payments and seller payouts.
Can you migrate our existing store to a new platform?: Yes, platform migrations are a core part of our e-commerce work. We handle data migration (products, customers, orders, reviews), URL redirects for SEO preservation, and parallel running during transition. We've migrated stores from Magento 2 to headless Next.js/Shopify, from WooCommerce to custom platforms, and from legacy custom systems to modern architectures.
How do you optimise e-commerce sites for search engines?: We build e-commerce sites with technical SEO as a core requirement: server-side rendering for all product and category pages, structured data (Product schema with price, availability, and reviews), canonical tags for filtered/sorted pages, fast Core Web Vitals, and sitemap generation. We avoid common e-commerce SEO issues like duplicate content from faceted navigation and thin category pages.