István Mező, Developer in Budapest, Hungary
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István Mező

Verified Expert  in Engineering

Software Developer

Budapest, Hungary
Toptal Member Since
October 1, 2021

Istvan is a tech lead with eight years of experience building applications used by millions of people worldwide. He has been using Angular since its release, and he can handle back-end tasks in multiple languages, such as Node.js, Python, and Java. Istvan has been the lead engineer on a number of projects, working closely with other domain experts while delegating and implementing technical tasks.


Angular, NgRx, Ionic, Capacitor, Nx, Figma, JavaScript, TypeScript, HTML, CSS...
JavaScript, TypeScript, Angular, AngularJS, Node.js, Java, Spring, PostgreSQL...
Miro Digital Technologies
JavaScript, TypeScript, Angular, GraphQL, Apollo, Hasura, APIs, Teamwork...




Preferred Environment

Ubuntu, MacOS, Visual Studio Code (VS Code), Slack, Jira

The most amazing...

...product I've worked on is cozycozy, an accommodation metasearch engine used by millions of people since its launch.

Work Experience

Senior Front-end Developer | Tech Lead

2021 - PRESENT
  • Worked for an international healthcare tech company. Shipped a new feature for our enterprise clients under a tight deadline while collaborating closely with other team members.
  • Transitioned the front-end repositories to a common Nx monorepo, improving the code's structure and the developer's experience.
  • Introduced domain-driven design (DDD) and development when planning new features.
  • Set up a working E2E test suite and coached junior colleagues on how to develop robust tests.
  • Led the design and development of full features while working closely with the product, marketing, and clinical teams.
  • Spearheaded the development of a new app and oversaw the closed trial testing on iOS, Android, and the web.
Technologies: Angular, NgRx, Ionic, Capacitor, Nx, Figma, JavaScript, TypeScript, HTML, CSS, Scrum, Jira, HTML5, Firebase, iOS, Android, API Design, UI Development, UI Design, UX Design, CSS3, Web Development, Technical Writing, Documentation, API Documentation, Payment APIs, NestJS, Technical Leadership

Senior Full-stack Developer

2018 - 2021
  • Developed a significant part of the Angular front-end application during the initial launch.
  • Maintained and developed new features of the accommodation deduplication framework, including improving the deployment time by 80%.
  • Planned and developed a recommendation framework that sends hundreds of email offers to registered users every day.
  • Assisted in SEO internationalization of pages to 25+ languages, including the SEO content pipeline and CMS.
  • Created a data pipeline for our production data, including the live monitoring, daily reports, and interface for our business analysts.
Technologies: JavaScript, TypeScript, Angular, AngularJS, Node.js, Java, Spring, PostgreSQL, PySpark, HTML, Express.js, HDFS, HBase, Hadoop, Apache Airflow, Docker, Docker Compose, Kubernetes, GitLab, GitLab CI/CD, MySQL, Spark SQL, gRPC, APIs, RxJS, React, NgRx, REST, REST APIs, Component Libraries, Angular Material, Front-end, MongoDB, Full-stack, Full-stack Development, CSS, HTML5, Firebase, API Design, UI Development, UI Design, UX Design, NoSQL, CSS3, WebSockets, Web Development, Calendars, Search Engine Optimization (SEO), Google SEO, Organic SEO, Server-side Rendering (SSR), Cron, Terraform, SQL, Spring Boot

Senior Front-end Consultant

2020 - 2020
Miro Digital Technologies
  • Streamlined the internal processes related to the front-end development by increasing productivity and allowing faster iterations.
  • Communicated with the external UI/UX team, guided them to technical decision-making, and reviewed their code.
  • Created and developed the front-end user stories, including the planning and development of an entire feature.
Technologies: JavaScript, TypeScript, Angular, GraphQL, Apollo, Hasura, APIs, Teamwork, Amazon Web Services (AWS), Component Libraries, PrimeNG, Front-end, CSS, Jira, HTML5, Amazon S3 (AWS S3), AWS Lambda, UI Development, UI Design, UX Design, CSS3, WebSockets, Bitbucket, Web Development, Calendars, HTML, Documentation

Front-end Developer

2018 - 2018
  • Laid the groundwork for developing a brand new user-facing Angular front-end application, including researching the state-of-the-art practices for the similar progressive web app (PWA).
  • Presented the state-of-the-art PWA research findings to other developers during internal meetings, Hungarian meetups, and Barcelona's head office meetings.
  • Implemented features in the legacy Liligo application written in native JavaScript and solved the long outstanding bugs, which resulted in increased revenue.
Technologies: JavaScript, TypeScript, Angular, APIs, Teamwork, RxJS, NgRx, Front-end, Agile, CSS, Jira, HTML5, UI Development, CSS3, WebSockets, Web Development, HTML, Search Engine Optimization (SEO), Organic SEO, Server-side Rendering (SSR), Documentation

Software Engineer

2016 - 2017
GE Healthcare
  • Acted as a core member of a new Angular front-end team, developing a completely new product for professional athletes.
  • Fixed bugs and added new features to a cloud health management application using AngularJS and Spring.
  • Performed extensive testing on every level to comply with the regulations for medical devices.
Technologies: Angular, JavaScript, TypeScript, HTML, CSS, E2E Testing, Java, Spring, Integration Testing, Unit Testing, IntelliJ IDEA, AngularJS, Test-driven Development (TDD), Behavior-driven Development (BDD), Scrum, REST, REST APIs, Front-end, Agile, Selenium, HTML5, UI Development, CSS3, Web Development, Documentation, SQL, Spring Boot

cozycozy Search Engine
cozycozy is an accommodation metasearch engine that allows travelers to compare the full range of available accommodation options.

I participated in different parts of this project, from developing the front and back end to taking care of the data infrastructure and building various data pipelines.

ng2-flatpickr is a lightweight open-source Angular wrapper for flatpickr, used in reactive forms inside Angular. Since its initial release, it has been downloaded more than 500,000 times and is still used by hundreds of people every day.

Article on a New CSS Solution
Wrote an article called "Finally, a CSS only solution to :hover on touchscreens" that deals with solving a long-time CSS problem. This topic was not covered in-depth, but it came up during my daily work. It has been read more than 150,000 times and is still getting more than a hundred hits every day.
2007 - 2012

Bachelor's Degree in Mechatronics Engineering

Budapest University of Technology and Economics - Budapest, Hungary


REST APIs, Node.js, jQuery, PySpark, RxJS, React, NgRx, PrimeNG


Sequelize, Docker Compose, Capacitor, Bitbucket, Slack, GitHub, NPM, Apache Airflow, GitLab, GitLab CI/CD, Spark SQL, IntelliJ IDEA, Figma, Jira, Cron, Terraform


Angular, Express.js, AngularJS, Ionic, Spring Boot, Spring, Hadoop, gRPC, Angular Material, Bootstrap, Selenium, NestJS


JavaScript, TypeScript, CSS, HTML, HTML5, CSS3, SQL, Java, Python, GraphQL


MySQL, PostgreSQL, HDFS, HBase, Hasura, MongoDB, Amazon S3 (AWS S3), NoSQL


REST, Search Engine Optimization (SEO), E2E Testing, Unit Testing, Test-driven Development (TDD), Behavior-driven Development (BDD), Scrum, Agile, UI Design, UX Design


Ubuntu, Docker, MacOS, Kubernetes, Amazon Web Services (AWS), Firebase, iOS, Android, AWS Lambda, Visual Studio Code (VS Code)


Front-end, UI Development, Web Development, Server-side Rendering (SSR), Technical Writing, APIs, Full-stack, API Design, WebSockets, Documentation, API Documentation, Software Development, Apollo, Teamwork, Integration Testing, Component Libraries, Nx, Full-stack Development, Calendars, Google SEO, Organic SEO, Payment APIs, Technical Leadership

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