Orsolya Belasitz, Developer in London, United Kingdom
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Orsolya Belasitz

Verified Expert  in Engineering

Software Developer

London, United Kingdom
Toptal Member Since
September 30, 2019

Orsolya has been working as a full-stack developer for several years on both smaller and larger-scale projects. She has a strong detail-oriented mindset, loves solving exciting problems, and enjoys working both independently and as part of a team. While Orsolya considers herself language-agnostic and always eager to learn new technologies, she is most experienced in HTML/CSS, React, Node.js, REST APIs, C#, Docker, SQL, and NoSQL.


React, Ruby on Rails (RoR), PostgreSQL
Microsoft SQL Server, Web API, C#, TypeScript, Redux, React
Java, Docker, Cassandra, Electron, TypeScript, React




Preferred Environment

GitHub, Visual Studio Code (VS Code)

The most amazing...

...website I've worked on was a popular auction site. It's amazing to work on something that millions of people use every day and I can see the impact of my code.

Work Experience

Contract Software Engineer

2020 - PRESENT
  • Developed a web app from almost the beginning to deliver a platform for business users.
  • Delivered regular bug fixes through regular testing of the application.
  • Collaborated with the design team to improve user experience.
Technologies: React, Ruby on Rails (RoR), PostgreSQL

Full-stack Software Consultant

2019 - 2020
  • Improved the UI of existing platforms working with no design team involved.
  • Implemented third-party authentication with Okta and Microsoft Azure.
  • Added unit tests to existing projects, improved the test coverage and overall project stability to get fewer bugs.
  • Integrated dashboards into a data analytics platform.
Technologies: Microsoft SQL Server, Web API, C#, TypeScript, Redux, React

Software Engineer Consultant

2018 - 2019
  • Contributed to the build of a greenfield front end for a trading surveillance platform.
  • Designed the coding patterns for front-end development.
  • Performed frequent code reviews and peer programming.
  • Designed and implemented a cross-window authentication framework via OpenFin.
  • Collaborated with back-end developers on API designs.
  • Implemented a graph visualization of large historical data.
Technologies: Java, Docker, Cassandra, Electron, TypeScript, React

Full-stack Software Engineer

2018 - 2018
  • Contributed to the build of a client-facing application for an AI startup.
  • Delivered full-stack features with unit testing.
  • Gathered user feedback on front-end functionalities.
  • Performed frequent code reviews and peer programming.
  • Developed large multi-page forms.
Technologies: Cassandra, Node.js, React

Full-stack Software Engineer

2017 - 2018
  • Developed the main software for a global logistics company.
  • Researched and analyzed data deduplication algorithms.
  • Improved processes by giving feedback to the wider team.
  • Performed code reviews and peer programming.
Technologies: Microsoft SQL Server, JavaScript, C#

Full-stack Software Engineer

2016 - 2017
Trade Me
  • Participated in the full-stack development of the top New Zealand auction website.
  • Performed frequent code reviews and peer programming.
  • Delivered full-stack functionalities in a strongly Agile manner.
  • Developed secure payment flow processing credit card and balance payments.
Technologies: Mercurial, SQL, C#, .NET, REST APIs, TypeScript, AngularJS

Software Development Engineer Consultant

2016 - 2016
  • Consulted on continuous deployment for a New Zealand bank.
  • Developed a PowerShell script library to support continuous development across multiple teams.
  • Advised on best practices.
  • Consulted on improving inter-team collaboration processes.
Technologies: Windows PowerShell, TFS

Full-stack Software Engineer

2011 - 2015
Morgan Stanley
  • Collaborated with an international team on the operation, support, and troubleshooting of an in-house built configuration management system and related tools.
  • Worked in a scrum development team on a custom configuration management system.
  • Performed frequent code reviews and peer programming.
Technologies: Windows Presentation Foundation (WPF), Windows PowerShell, Microsoft SQL Server, .NET, C#

Choose Your Dog Website

This is a full-stack project that I made in order to experiment with a variety of technologies. I developed the website using the following technologies: React, Node.js, Docker, Kubernetes, Terraform, and Google Cloud.

Chat Application Using Socket.IO

A chat application built with Socket.IO, Node.js, Express, React, React Context, React Hooks, and TypeScript. It can retain chat messages and re-join the chat room. Themes and user settings are saved through local storage and React Context.

Athena Mobile App

Developed a mobile app for Athena, an open source festival logistic management project. The mobile app is written in React Native and is currently published live on both the iOS App Store and the Android Play Store.
2005 - 2011

Bachelor of Science Degree in Computer Engineering

Budapest University of Technology and Economics - Budapest, Hungary


React, Node.js, REST APIs, Passport.js, Web API


GitHub, Mercurial, Webpack 4, Keycloak, Git, Webpack, TFS, React Apollo


JavaScript, TypeScript, GraphQL, Python, C#, SQL, HTML5, CSS, Java


JSON Web Tokens (JWT), OAuth 2, Jest, Selenium, Electron, Redux, AngularJS, .NET, Windows PowerShell, Windows Presentation Foundation (WPF), Ruby on Rails (RoR), React Native


MySQL, Microsoft SQL Server, Cassandra, MongoDB, NoSQL, PostgreSQL


Continuous Integration (CI), Continuous Deployment, Agile Software Development


OpenFin, Firebase, Visual Studio Code (VS Code), Docker


Debugging, Troubleshooting, Security, Third-party Authentication, Authentication, User Authentication, APIs, Okta, Enzyme, Collaborative Design

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