Software engineer with 6+ years of experience building scalable React and Next.js micro-frontend applications using modern frontend engineering practices (UI components, UX-focused optimization, and cross-browser tooling). Strong background in performance, SEO, and reliability through observability, monitoring, and Sentry/Grafana integration. Also experienced with micro-frontend and platform integrations (Node.js proxy layers, GraphQL/REST, payment integrations), CI/CD automation, Docker/Kubernetes deployments, and mentoring teams to improve testing and development workflows.

Rainald Balog

Software engineer with 6+ years of experience building scalable React and Next.js micro-frontend applications using modern frontend engineering practices (UI components, UX-focused optimization, and cross-browser tooling). Strong background in performance, SEO, and reliability through observability, monitoring, and Sentry/Grafana integration. Also experienced with micro-frontend and platform integrations (Node.js proxy layers, GraphQL/REST, payment integrations), CI/CD automation, Docker/Kubernetes deployments, and mentoring teams to improve testing and development workflows.

Available to hire

Software engineer with 6+ years of experience building scalable React and Next.js micro-frontend applications using modern frontend engineering practices (UI components, UX-focused optimization, and cross-browser tooling). Strong background in performance, SEO, and reliability through observability, monitoring, and Sentry/Grafana integration.

Also experienced with micro-frontend and platform integrations (Node.js proxy layers, GraphQL/REST, payment integrations), CI/CD automation, Docker/Kubernetes deployments, and mentoring teams to improve testing and development workflows.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Beginner
Beginner
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Language

Hungarian
Fluent
English
Advanced

Work Experience

Senior Front-End Engineer at Heureka Group (Árukereső / Hеu reka ső, he urekesо .h u)
June 1, 2022 - Present
Led development of React/Next.js micro-frontends (Shop Admin, Internal Admin, User Profile, Product Q&A, Checkout, Homepage, Promotions) serving 4 countries. Rewrote a Node.js proxy layer supporting the checkout platform. Implemented OpenTelemetry-based observability and integrated Sentry/Grafana monitoring to reduce time to detect production issues. Co-developed Heureka internal Hasty UI component library used across nine frontend services, reducing duplicate components. Integrated multi-country payment flows (3DSecure card payments, Google Pay, Apple Pay, online banking, and parcel locker via Google Maps) to improve payment success rate. Delivered SEO-focused campaign pages using Next.js SSR and Zod validation, increasing organic traffic; also improved Product/Category Q&A platforms for indexed, user-generated content. Improved Core Web Vitals via code splitting, image optimization, and SSR tuning. Streamlined GitLab CI/CD and Docker-based deployments. Mentored junior engineers (c
Senior Front End Engineer at Heureka Group
June 1, 2022 - Present
Developed React/Next.js micro-frontends (Shop Admin, Internal Admin, User Profile, Product Q&A, Checkout, Homepage, Promotions) serving 4 countries. Rewrote a Node.js proxy layer for the checkout platform. Implemented OpenTelemetry-based observability and integrated Sentry/Grafana monitoring, reducing mean time to detect production issues. Co-developed an internal Hasty UI component library across nine frontend services, reducing duplicated components. Integrated Adyen payment flows (3D Secure, card payments, Google Pay, Apple Pay, online banking, and Parcel Locker via Google Maps) across multi-country checkout. Delivered SEO-focused campaigns using Next.js SSR and Zod validation, improving organic traffic. Delivered SEO-optimized Product/Category Q&A platforms, growing indexed, user-generated content. Improved Core Web Vitals via code splitting, image optimization, and SSR tuning. Streamlined GitLab CI/CD pipelines and Docker-based deployments. Mentored junior engineers (5–10) on fr
Front-End Engineer at AROBS Transilvania Software (arobs.com / travelport.com)
August 1, 2021 - June 1, 2022
Maintained existing web application features and implemented new functionality in a micro-frontend setting. Collaborated with the UX team, performed UI work, and supported releases and deployments via Azure Pipelines. Developed and tested updates using Jest; reviewed pull requests and ensured quality through unit/integration/E2E approaches. Technology stack included React, Redux, Jest, GraphQL, Azure Pipelines, and Kubernetes. Worked on frontend development, UI engineering, responsiveness, design systems, and end-to-end quality assurance.
Front End Engineer at AROBS Transilvania Software / Travelport
August 1, 2021 - June 1, 2022
Maintained existing web features and implemented new functionality. Collaborated with the UX team. Performed unit testing with the Jest framework and created releases and deployed updated web app versions via Azure Pipelines. Reviewed pull requests and worked with React/Redux, GraphQL, and micro-frontend architectures. Technologies: React, Redux, Jest, GraphQL, Azure Pipelines, Kubernetes.
Front End Engineer at AROBS Transilvania Software
August 1, 2021 - June 1, 2022
Maintained existing web features, implemented new functionality, and collaborated with the UX team. Performed unit testing using the Jest framework. Created releases and deployed new versions of the web app using Azure Pipelines. Reviewed pull requests. Technologies used: React, Redux, Jest, GraphQL, Azure Pipelines, Kubernetes.
Senior Software Engineer at One dot AG
May 1, 2020 - July 1, 2021
Maintenance of existing features, design improvements, and implementation of new functionality in a more modern architecture. Performed unit, UI, and E2E testing using Cypress. Worked with GraphQL for web app integration and AWS API integration. Implemented/updated integrations with Keycloak API. Technologies included React, Redux, TypeScript, Cypress, Scala, Keycloak API, GraphQL, and AWS, plus TeamCity and Docker web developer workflows.
Senior Software Engineer at Onedot AG
May 1, 2020 - July 1, 2021
Maintenance of existing features, design and implementation of new functionalities in a more complex architecture. Built UI and performed E2E testing with Cypress. Designed with GraphQL for the web app integration and integrated AWS API with Scale Keycloak API. Technologies used: React, Redux, TypeScript, Cypress, Scala, Keycloak API, GraphQL, AWS API, TeamCity, Docker Web Developer.
Frontend Developer at AROBS Transilvania Software
December 1, 2019 - February 1, 2020
Built React/Node.js web applications with user authentication and mini-games using Redux and MySQL. Contributed to UI development, testing, and deployment in an Agile Scrum team using Git. Developed and supported features in a production-like environment with appropriate testing and release practices.
Front End Developer (React/Node.js) at AROBS Transilvania Software
December 1, 2019 - February 1, 2020
Built a React/Node.js web application with user authentication and mini-games using Redux and MySQL. Contributed to UI development, testing, and deployment in an Agile Scrum team using Git.
Senior Software Engineer at Onedot AG
December 1, 2019 - February 1, 2020
Maintained existing features and implemented new functionalities in a monorepo architecture. Worked on UI and E2E testing using Cypress. Performed database maintenance. Implemented GraphQL for the web app and integrated AWS API with Scal e Keycloak API. Technologies: React, Redux, TypeScript, Cypress, Scala, Keycloak API, GraphQL, AWS API, TeamCity, Docker.
Front-End Developer at AROBS Transilvania Software
December 1, 2019 - February 1, 2020
Built a React/Node.js web app with user authentication and mini-games using Redux and MySQL. Contributed to UI development, testing, and deployment in an Agile Scrum team using Git.
Intern (Web Developer) at Cylex Intern
September 1, 2018 - October 1, 2018
Worked on a JavaScript web application; implemented responsive design and object-oriented programming concepts. Assisted in development with highly skilled employees.
Intern at Cylex
September 1, 2018 - October 1, 2018
Developed a JavaScript web application with responsive design and object-oriented programming. Worked with highly skilled employees and supported delivery using web development best practices.
Web Developer (Intern) at Cylex Intern
September 1, 2018 - October 1, 2018
Developed a JavaScript web application. Implemented responsive design and object-oriented programming.
Intern at Cylex International
September 1, 2018 - October 1, 2018
Developed a JavaScript web application. Worked on responsive design and object-oriented programming. Collaborated with highly skilled employees.

Education

Bachelor of Science, Computer Science and Mathematics at Babeș-Bolyai University
January 1, 2016 - July 1, 2019
at Simion Bărnuțiu National College
January 1, 2012 - January 1, 2016
at Onedot AG
May 1, 2020 - July 1, 2021
Bachelor of Science, Computer Science and Mathematics at Babeș-Bolyai University
January 1, 2016 - January 1, 2019
Front End Engineer at onedot AG
May 1, 2020 - July 1, 2021
Bachelor of Science, Computer Science and Mathematics at Babeş-Bolyai University
January 1, 2016 - January 1, 2019
at Simion Bărnuțiu National College
January 1, 2012 - January 1, 2016
at Onedot AG
May 1, 2020 - July 1, 2021
Bachelor of Science, Computer Science and Mathematics at Babes-Bolyai University
January 1, 2016 - January 1, 2019
at One dot AG
May 1, 2020 - July 1, 2021

Qualifications

WebPack 5 Ninja
January 1, 2023 - July 30, 2026
Claude with the Anthropic API
March 1, 2026 - July 30, 2026
Introduction to Agent Skills
March 1, 2026 - July 30, 2026
Introduction to Model Context Protocol
March 1, 2026 - July 30, 2026
Claude Code in Action
April 1, 2026 - July 30, 2026
Web pack 5 Ninja
January 1, 2023 - July 30, 2026
Claude Education: Introduction to agent skills
March 1, 2026 - July 30, 2026
Introduction to Model Context Protocol
March 1, 2026 - July 30, 2026
Claude with the Anthropic API
March 1, 2026 - July 30, 2026
Claude Code in Action
April 1, 2026 - July 30, 2026
Introduction to Agent Skills (Anthropic)
March 1, 2026 - July 30, 2026
Introduction to Model Context Protocol (Anthropic)
March 1, 2026 - July 30, 2026
Claude with the Anthropic API (Anthropic)
March 1, 2026 - July 30, 2026
Claude Code in Action (Anthropic)
April 1, 2026 - July 30, 2026
Udem y: Webpack 5 Ninja (2023)
January 1, 2023 - July 30, 2026
Webpack 5 Ninja
January 1, 2023 - July 30, 2026
Anthropic Education: Introduction to agent skills
March 1, 2026 - July 30, 2026
Anthropic Education: Introduction to Model Context Protocol
March 1, 2026 - July 30, 2026
Claude with the Anthropic API
March 1, 2026 - July 30, 2026
Claude Code in Action
April 1, 2026 - July 30, 2026

Industry Experience

Software & Internet, Computers & Electronics, Education, Professional Services, Transportation & Logistics, Retail, Financial Services

Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Beginner
Beginner
See more