Sergey Vareyko / E-commerce Platforms

E-commerce platform development: storefronts and back offices

This page is for brands that need more than a template shop, and for companies running larger commerce or payment systems that need a backend engineer who has worked inside one. I'm Sergey Vareyko, a software architect with 15+ years in Java and Spring. My e-commerce platform development work spans three scales: a single-JAR storefront and admin CMS for a handmade ceramics brand, a US customer engagement and conversion platform for large brands from 2010 to 2016, and the merchant onboarding platform of a European payment provider.

What I build

  • Storefront and admin in one deployable. A Spring Boot backend that serves the REST API and the built Vue application — public storefront and admin panel — from one JAR: one artifact to deploy, one process to run.
  • A custom e-commerce back office. Product and content pages edited in a WYSIWYG editor with tables, built-in image processing, analytics dashboards, and AI integration aimed at simplifying the shop's processes.
  • SEO that follows the catalog. Server-rendered SEO pages next to the single-page app, dynamic SEO, and readable URLs generated from Russian names by transliteration.
  • Protection from the start. Rate limiting, HTML sanitizing, token-based authentication and caching.
  • Payments and merchant onboarding. A registration API, rule-based validation and automated provisioning across downstream systems, including alternative payment methods such as Alipay, Apple Pay, Klarna, Sofort and WeChat Pay. Card payments are also part of the salon booking app I worked on.
  • Conversion and engagement. Server-side logic and APIs for live chat, guided customer flows, personalization and analytics-driven engagement.
  • Operations portals. Search and filters over registrations, step and data-flow views, request and response payload viewers and per-system performance breakdowns, so operators can see which step a registration is on and where it stopped.

For a single brand, the right answer is usually one compact application that the owner can run. For a platform with partners, it is an integration module per external system, a contract that new partners plug into through configuration, and integration tests that keep that contract honest. Rule engines of the kind AMS uses are also at the core of the custom business systems I build.

How I work

I start with the business requirements and turn them into a solution: structure, stack, integrations and how it will scale. That is the job I have done in technical presales and solution design for new client engagements, and I stay on as the architect through implementation. For a shop, discovery is about the catalog, the content, the payment provider and the systems the shop already uses; for a platform, about partners, contracts and failure modes.

Then comes a working version early, and iterations from there. I own the result end to end: backend, admin, storefront, deployment. You receive a running storefront and back office, a codebase on mainstream tools (Spring Boot, Vue, TypeScript), and for platform work, tests that cover the integration flows. On a platform that already exists, I start by reading the system and its contracts before changing them.

Projects in this domain

Tobo — Author, 2026. A storefront and admin CMS for TOBO_ceramics, a brand of handmade ceramics: sculpture, home ceramics, masks and a sale section. The Spring Boot backend serves the REST API and the Vue storefront and admin from one fat JAR, with built-in image processing, WYSIWYG content editing, rate limiting and Russian-to-ASCII slug generation. Dynamic SEO, analytics and AI integration are part of the platform.

TouchCommerce — Software Engineer, 2010–2016. A US-based enterprise customer engagement and e-commerce conversion platform: live chat, guided self-service, personalization, customer analytics and automated engagement for large brands. I implemented server-side business logic and APIs for live chat and guided flows, built backend and frontend for the real-time chat including co-browsing, and optimized event storage for performance and data retrieval.

AMS — Automated Merchant Setup (Wirecard) — Software Engineer, 2018–2020. The merchant onboarding platform of a European payment provider: a partner submits a registration through a REST API, a business-rule engine validates it, and a resumable workflow provisions the merchant across around twenty downstream systems. I extended the validation engine (declarative XML rule sets, Java rules, environment-specific overrides), delivered Original Credit Transaction support end to end, and hardened adapters to partner systems including Klarna. The codebase has 41 Maven modules and about 260,000 lines of Java.

Frequently asked questions about e-commerce platform development

Why a custom e-commerce back office instead of a ready-made platform?

A ready-made platform is the right choice when your catalog and your process fit it. A custom build pays off when the shop is also the brand's site, with its own pages and design, or when the back office has to talk to systems a platform does not know. Tobo is the first case: a designer platform with e-commerce, with content pages edited next to the catalog — the same approach as my content websites with a custom CMS.

How long does it take?

It depends on scope. What determines it: the size and structure of the catalog, the payment provider and how much of checkout it handles, integrations with accounting or other systems, the amount of content to move over, and how custom the design is. I estimate after a first look at the requirements.

Which stack do you use?

Java 21 and Spring Boot on the backend, MongoDB or a relational database, Vue 3 with TypeScript on the front, and Tailwind CSS or a component library for the UI. Larger platforms add message queues.

Who maintains the shop, and where is it hosted?

Day-to-day content, products and pages are managed in the admin panel. A single-JAR application runs on one server, yours or one we choose together; support after launch and access to the repository are agreed at the start.

Need an engineer with experience in e-commerce platform development? Write to me — a few lines about the task are enough — or look through my CV.