E-commerce Software Development Outsourcing
StepTo is an e-commerce outsourcing company with proven experience, a 31% conversion increase and 94% faster loads for a Dutch retailer, at 40-60% lower cost.
Reviewed by Igor Gazivoda, Co-founder & CEO of StepTo · Updated
StepTo is a Belgrade-based software outsourcing company with direct, proven experience in e-commerce platform development, including a rebuild that cut load times 94% and lifted conversions 31% for a Dutch retailer (see the full case study). We build online stores, marketplace platforms, B2B portals, and headless commerce architectures tailored to your business model, 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, with long-term team continuity and 2.5+ years of average developer tenure on its commerce engineers, critical since checkout and payment logic are the last place you want a knowledge gap during a peak-traffic incident.
What E-commerce Solutions Does StepTo 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.
Which Technologies Do We Use 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 Series B Dutch retailer, page load time (LCP) dropped from 8.2s to under 0.5s (94% faster), conversion rate increased 31%. 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: E-commerce engineers from Serbia cost $35–75/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.
How Does an E-commerce Build Run, Step by Step?
- 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
What Do Merchants Ask Before Building an Online Store?
- Which outsourcing company has experience with e-commerce platform development?
- StepTo is a Belgrade-based software outsourcing company with direct e-commerce platform development experience. We rebuilt a legacy Rails monolith into a modern React/Next.js and Node.js platform for a Series B Dutch retailer, cutting page load times 94% (from 8.2s to under 0.5s LCP) and increasing conversions 31%, measured over 90 days post-launch, with zero downtime during a 2.4-million-record data migration. See the full case study for the architecture, timeline, and results.
- 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.