Gyula Szvitek
I am a Full-Stack Engineer with 10+ years of experience architecting high-availability web applications, distributed microservices, and modern frontend ecosystems. Specialized in React, TypeScript, Node.js, and Cloud Infrastructure (Azure / AWS), with a proven track record delivering complex enterprise software, greenfield product launches, automated workflows, and event-driven backend systems. Skilled in leading cross-service migrations, optimizing system performance, and collaborating with international engineering teams.

Express
Jest
MongoDB
Nest.js
Next.JS
NodeJS
React
Redux
Sanity
Tailwind CSS
Typescript
Express
Jest
MongoDB
Nest.js
Next.JS
NodeJS
React
Redux
Sanity
Tailwind CSS
Typescript
SWYTECH.dev
FeaturedPersonal Portfolio — A high-performance central hub highlighting my web development career, technical skills, and featured projects. Features live interactive demos, custom UI components, and my professional background.
Sanity
Typescript
Next.JS
React
Figma
Tailwind CSS
Sanity
Typescript
Next.JS
React
Figma
Tailwind CSS
CyberCN UI
FeaturedCybercn UI is a modern component architecture reimagining the original CSS library. Features a bold cyber aesthetic, accessible components, live code examples, and full documentation.
Typescript
Next.JS
React
Tailwind CSS
Typescript
Next.JS
React
Tailwind CSS
TB-Toolbox
FeaturedHigh-performance troop calculator and strategy suite delivered as an offline-first PWA. Features a dual-tier build: a lightweight Vanilla JS engine alongside an advanced React & TypeScript app.
Javascript
HTML
Typescript
Bootstrap
React
Javascript
HTML
Typescript
Bootstrap
React
Segen Ltd.
London
Nov 2024 — Present
Software Developer
WebsiteThe UK’s Leading Renewables Distributor
Engineered a comprehensive full-stack rewrite, transitioning a legacy monolithic RM/SOP platform into a modern TypeScript monorepo. Built custom React extension apps to significantly enhance the core Shopify e-commerce experience. Executed a seamless zero-downtime migration, architecting cross-system data synchronization and maintaining backward compatibility to keep both legacy and modern systems live simultaneously. Gained deep production experience in Azure cloud infrastructure, CI/CD pipelines, and enterprise-grade React architecture.
Nest.js
NodeJS
MySQL
Redis
Azure
Grafana
OpenTelemetry
React
Tailwind CSS
CSS
HTML
Typescript
Figma
Git
GraphQL
JestDual-System Architecture & Storefront Launch
Actively contributed to full-stack feature development during a greenfield Shopify storefront launch while maintaining legacy platform infrastructure; integrated Node.js middleware APIs to manage real-time product, order, and account data sync across both systems.
Shopify React Extension Apps
Engineered new features and UI components within custom React-based Shopify app extensions and admin proxy applications, bridging complex backend rules with modern storefront interfaces to support custom B2B buying flows.
Order & Fulfillment Business Logic
Built real-time validation checks within Node.js fulfillment microservices, dynamically holding or releasing customer orders based on live account balance rules and warehouse picking conditions.
Invoice & Account Features
Developed responsive React frontend interfaces and Node.js backend integrations within the Shopify admin proxy app, enabling self-service invoice tracking, status verification, and proof-of-payment uploads.
Backend API Reliability & Bug Resolution
Diagnosed and resolved high-volume event processing errors in Node.js microservices, updating payload validation to eliminate 1,450+ weekly execution failures and clear blocked message queues within 3 days.
Global Agile Collaboration
Partnered with distributed international engineering teams, product managers, and UX designers in an agile environment, maintaining high code quality through TDD, component testing, and peer code reviews.
Freelance Developer
London
Apr 2023 — Nov 2024
Professional Development
Full-Stack Engineering & Continuous Learning
Dedicated focused development time to mastering modern full-stack TypeScript ecosystems. Built high-performance, edge-rendered web applications using React, Next.js, and Vue. Parallelly earned industry certifications and deepened practical expertise in cloud architecture, modern design patterns, and performance optimization techniques to stay ahead of evolving web technologies.
Express
Nest.js
NodeJS
MongoDB
PostgresSQL
Astro
D3
Next.JS
Nuxt JS
React
Redux
Tailwind CSS
Vue.js
CSS
HTML
Javascript
Typescript
Figma
Git
Jamstack
Jest
SanityModern React & Next.js Mastery
Acquired deep proficiency in React, Next.js, and modern SSR/SSG full-stack ecosystems.
Industry Certification & Verification
Completed formal industry certifications to validate technical domain expertise.
IT Advisory & Side Project Delivery
Engaged in IT consultancy projects and collaborated on modern web application side projects.

HP (via Oneflow Acquisition)
London
Feb 2019 — Apr 2023
Full Stack typescript developer (Cloud Engineer 3)
WebsiteEnterprise Print Workflow & Automation Software
Contributed to modernizing Oneflow’s core enterprise printing platform—a startup solution later acquired by HP and integrated into HP Site Flow, their flagship global cloud-based print automation software. Drove frontend modernization by migrating core modules from AngularJS to Vue.js, developed new microservice APIs using Node.js and MongoDB, and established comprehensive unit/integration test suites. Managed high-availability infrastructure using Docker, Kubernetes (EKS), and AWS services (S3, CloudFront, SNS/SQS) with Sentry and New Relic monitoring, maintaining automated deployments via CircleCI and building internal management tooling in React.
Express
NodeJS
MongoDB
AWS
CircleCI
Docker
Grafana
Kubernetes
Terraform
Bootstrap
Vue.js
CSS
HTML
Javascript
Typescript
Cypress
Git
Jest
MochaVue.js Frontend Modernization
Rewrote legacy AngularJS frontend to Vue.js 2, modernizing codebase and architecture.
Kubernetes to Amazon EKS Migration
Led backend application migration from custom K8s to AWS EKS, updating CI/CD pipelines.
JavaScript to TypeScript Migration
Executed application-wide migration from JavaScript to strongly typed TypeScript.
Enterprise Feature Delivery & Support
Maintained frontend/backend applications, delivering customer-requested features and bug fixes.
Sprint Backlog & Bug Fortnight
Spearheaded dedicated bug fortnight sessions to clear backlog debt and improve application stability.

SQS Ltd.
London
Nov 2016 — Feb 2019
Full Stack Software developer
WebsiteLeading Utilities Reinstatement & Infrastructure Provider
Contributed as part of a core engineering team developing Ontrack, a proprietary cloud-based work management system designed specifically for utility and street works reinstatement. Built Ontrack Lite as an initial high-performance proof-of-concept using Angular, Node.js, and MongoDB. Following its success, helped spearhead the full modernization of the company’s legacy PHP architecture into a scalable, modern JavaScript codebase, dramatically improving system speed, reporting capabilities, and operational reliability.
Express
NodeJS
Symfony
MongoDB
MySQL
AWS
Jenkins
Angular
Bootstrap
CSS
HTML
Javascript
PHP
Typescript
Git
JestFull Stack Legacy PHP Rewrite
Rewrote legacy Symfony PHP system into a modern MEAN stack (Node.js, Angular 2+, MongoDB/MySQL).
Ontrack Lite System Launch
Developed and released the Ontrack Lite system as a lightweight proof-of-concept.
SOAP API Utility Integration
Integrated a major UK power supplier’s legacy system via SOAP API into Ontrack 2 & 3.

Betfect
London
Feb 2016 — Aug 2016
Lead PHP Developer
Innovative Social Sports Betting Platform
Developed features for an interactive social betting ecosystem that allowed users to create, share, discuss, and replicate betslips in real-time. Integrated complex third-party REST/WebSocket APIs from major global bookmakers (including Ladbrokes and William Hill), driving high-frequency data syncing, low-latency UI updates, and an engaging community-driven user experience.
Symfony
MySQL
CSS
HTML
Javascript
PHP
GitEngineering Team Leadership
Led a team of 3 developers while overseeing system updates and feature rollouts.
Symfony Core Framework Upgrade
Upgraded core platform framework to Symfony 2.7 to improve system stability.
William Hill Bookmaker Integration
Released direct William Hill API integration, coordinating directly with partner dev teams.
Wallet & Odds Comparison Engine
Integrated user wallets on betfect.com and implemented live odds comparison features.

