I am a results-oriented, resourceful software developer specializing in small and large-scale software design and development for a wide variety of companies. I have hands-on experience with JavaScript, CSS, and HTML, and I work well in Agile environments, delivering rapid results to customers. I am passionate, responsible and committed to delivering high-quality software.

István-Zoltán Fejér

I am a results-oriented, resourceful software developer specializing in small and large-scale software design and development for a wide variety of companies. I have hands-on experience with JavaScript, CSS, and HTML, and I work well in Agile environments, delivering rapid results to customers. I am passionate, responsible and committed to delivering high-quality software.

Available to hire

I am a results-oriented, resourceful software developer specializing in small and large-scale software design and development for a wide variety of companies.

I have hands-on experience with JavaScript, CSS, and HTML, and I work well in Agile environments, delivering rapid results to customers. I am passionate, responsible and committed to delivering high-quality software.

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Experience Level

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

Hungarian
Fluent
Romanian, Moldavian, Moldovan
Fluent
English
Fluent

Work Experience

Web Developer at Tengr.ai Artificial Intelligence K.F.T.
September 1, 2024 - Present
Developed Tengr.ai front-end app using NextJs, TailwindCSS and TypeScript; implemented version control with Git.
Web Developer at Diligencia Consulting Ltd.
June 30, 2024 - October 13, 2025
Part of a team that maintains a portal enabling customers to purchase company profiles. Worked with .NET Core, C#, Azure DevOps, jQuery, HTML, LESS, GraphQL; applied TDD for backend; used Git; built ClarifiedBy portal and diligenciagroup.com from start to finish.
Web Developer at Opus Energy
September 30, 2017 - October 13, 2025
Built and maintained a portal for managing energy accounts. Used Sitefinity (ASP.NET CMS), MVC widgets, JavaScript/jQuery, Kendo UI and OData for asynchronous data loading; used require.js for dynamic script loading; used TFS for version control.
Web Developer at IMUK Limited
February 28, 2015 - October 13, 2025
Developed websites (PHP, JavaScript, jQuery, HTML, Ajax, CSS); maintained multiple sites/hosting with or without CMS (cPanel, WordPress, DNN). Implemented front-end functionality and ensured cross-browser compatibility; engaged with clients to clarify requirements.
Web Developer at IMROM SRL
December 31, 2013 - October 13, 2025
Performed website development and maintenance (HTML, CSS, JS, PHP, cPanel); participated in client discussions to clarify needs; contributed to design process.
PHP Developer at GrafX SRL
May 31, 2011 - October 13, 2025
Collaborated with web designer and project manager to stay on target; provided creative input for dynamic, interactive, and user-friendly websites; adhered to coding best practices.
Software Developer at Evoline SRL
March 31, 2009 - October 13, 2025
Developed desktop applications using C# .NET; created utilities to support software development procedures; kept abreast of industry trends.
Web Developer at Tengr.ai Artificial Intelligence K.F.T.
September 1, 2024 - Present
Developed the front-end for the Tengr.ai web app using Next.js, TailwindCSS and TypeScript; implemented responsive UI and integrated Git for version control.
Web Developer at Diligencia Consulting Ltd.
June 1, 2024 - October 13, 2025
Maintained a portal enabling customers to purchase company profiles; used .NET Core, C#, Azure DevOps, jQuery, HTML, LESS, GraphQL. Followed TDD for backend; used Git for version control. Built ClarifiedBy portal and diligenciagroup.com from start to finish; participated in every development phase.
Web Developer at Opus Energy
September 1, 2017 - October 13, 2025
Built and maintained a customer portal to manage energy accounts; used Sitefinity (ASP.NET CMS), MVC widgets, JavaScript/jQuery, Kendo UI, and OData queries. Used require.js to load libraries as needed; used TFS for version control.
Web Developer at IMUK Limited
February 1, 2015 - October 13, 2025
Developed websites (PHP, JavaScript, jQuery, HTML, Ajax, CSS); maintained multiple sites with or without CMS (CPanel, WordPress, DNN). Focused on front-end functionality and cross-browser compatibility; engaged with clients to clarify requirements.
Web Developer at IMROM SRL
December 1, 2013 - October 13, 2025
Website development and maintenance (HTML, CSS, JS, PHP, Cpanel); collaborated with clients and followed the design process.
PHP Developer at GrafX SRL
May 1, 2011 - October 13, 2025
Collaborated with web designer and PM to deliver dynamic, interactive, user-friendly websites; followed best practices.
Software Developer at Evoline SRL
March 1, 2009 - October 13, 2025
Developed desktop applications in C#.NET; created utilities supporting software development processes; kept abreast of industry trends.
Web Developer at Tengr.ai Artificial Intelligence K.F.T.
September 1, 2024 - Present
Developed the Tengr.ai front-end application using Next.js, TailwindCSS, and TypeScript; collaborated with design and backend teams; maintained code with Git.
Web Developer at Diligencia Consulting Ltd.
June 1, 2024 - October 13, 2025
Part of a team maintaining a portal enabling customers to purchase company profiles; used .NET Core, C#, Azure DevOps, jQuery, HTML, LESS, GraphQL; practiced TDD on backend; contributed to end-to-end development of ClarifiedBy portal and diligenciagroup.com.
Web Developer at Opus Energy
September 1, 2017 - October 13, 2025
Built and maintained a customer portal; used Sitefinity CMS (ASP.NET), MVC widgets, JavaScript/jQuery, Kendo UI, and OData; loaded data asynchronously; used require.js to load libraries on demand; version control with TFS.
Web Developer at IMUK Limited
February 1, 2015 - October 13, 2025
Developed websites (PHP, JavaScript, jQuery, HTML, Ajax, CSS); maintained hosting with or without CMS (CPanel, WordPress, DNN); developed front-end functionality; collaborated with clients to clarify requirements and ensure a consistent look across browsers.
Web Developer at IMROM SRL
December 1, 2013 - October 13, 2025
Website development and maintenance (HTML, CSS, JS, PHP, cPanel); participated in client discussions to clarify needs; contributed to strategic thinking through all design stages.
PHP Developer at GrafX SRL
May 1, 2011 - October 13, 2025
Collaborated with web designer and project manager; provided creative input to make websites dynamic, interactive, and user-friendly; practiced best coding practices across projects.
Software Developer at Evoline SRL
March 1, 2009 - October 13, 2025
Developed desktop applications using C# .NET; created utilities to support software development procedures; stayed updated with industry trends.
Web Developer at Tengr.ai Artificial Intelligence K.F.T.
September 1, 2024 - October 27, 2025
Developed the front-end of the Tengr.ai app using NextJs, TailwindCSS and TypeScript. Implemented version control with Git.
Web Developer at Diligencia Consulting Ltd.
June 1, 2024 - June 1, 2024
Part of a team maintaining a portal that enables customers to purchase company profiles. Worked with .NET Core, C#, Azure DevOps, jQuery, HTML, LESS and GraphQL. Employed TDD for backend development and used Git for version control. Built ClarifiedBy portal and diligenciagroup.com from start to finish, participating in every phase of development.
Web Developer at Opus Energy
September 1, 2017 - September 1, 2017
Built and maintained a customer portal. Used Sitefinity (ASP.NET CMS), MVC widgets, JavaScript/jQuery, kendo UI and Odata for data loading. Implemented lazy loading with require.js and used TFS for version control.
Web Developer at IMUK Limited
February 1, 2015 - February 1, 2015
Developed websites (PHP, JavaScript, jQuery, HTML, Ajax, CSS). Managed hosting with or without CMS (CPanel, WordPress, DNN). Developed front-end functionality and collaborated with clients to clarify requirements, delivering consistent browser experiences.
Web Developer at IMROM SRL
December 1, 2013 - December 1, 2013
Performed website development and maintenance (HTML, CSS, JS, PHP, CPanel). Participated in client discussions to clarify needs and contributed to the design process.
PHP Developer at GrafX SRL
May 1, 2011 - May 1, 2011
Collaborated with web designer and project manager; contributed creative input to make websites dynamic, interactive, and user-friendly; adhered to standard coding practices.
Software Developer at Evoline SRL
March 1, 2009 - March 1, 2009
Developed desktop applications using C# .NET; created utilities to support software development procedures; stayed aligned with latest industry trends.

Education

Bachelor's Degree at Sapientia Hungarian University of Transylvania
January 1, 2004 - December 31, 2008
High School at Bolyai Farkas High School
January 1, 2002 - January 1, 2004
Bachelor's Degree in Computer Science at Sapientia Hungarian University of Transylvania
January 1, 2004 - January 1, 2008
High School at Bolyai Farkas High School
January 1, 2002 - January 1, 2004
Bachelor's Degree at Sapientia Hungarian University of Transylvania
January 1, 2004 - January 1, 2008
High School at Bolyai Farkas High School
January 1, 2002 - January 1, 2004
Bachelor's Degree in Computer Science at Sapientia Hungarian University of Transylvania
January 1, 2004 - January 1, 2008

Qualifications

Add your qualifications or awards here.

Industry Experience

Software & Internet, Professional Services, Energy & Utilities, Computers & Electronics, Media & Entertainment