John Tsevdos

Hi, I’m a front-end developer from Athens 🇬🇷 and I love "everything JavaScript" - browser and server. I'm working full-time at Trasys International and I'm sharing my JavaScript and React knowledge at Social Hackers Academy and Code.Hub! Say hello or keep scrolling!


Learn more about me

I'm a front-end developer that hand-crafts usable, elegant and effective web sites. I'm currently working for Trasys International (part of the NRB Group) an ICT company focusing on international public and corporate organisations. I have over 9 years of experience in front-end technologies and love working with JavaScript (ES2015 and above).

The last 2.5 years, I've been enjoying building components with React using various state management tools - redux and MobX - and of course react's extensive ecosystem ( react-router, redux-thunk, redux-saga, recompose, immer, reselect etc.). I'm also trying to improving my knowledge in functional and reactive programming by using / learning relevant JS libraries and languages such as ramda.js, RxJS, and ReasonML. Finally, I have hands-on experience in many other JavaScript frameworks and libraries such as backbone.js, underscore and lodash, jQuery, axios, moment.js and many more.

On the backend stack, I love working with node.js and express framework, but I also have decent knowledge in Ruby and Rails. I'm a huge fan of Linux OS (currently using Ubuntu), git, agile methodologies and always trying to do as much of TDD (Test-Driven Development) as possible.


I code stuff

React-validatus (npm package)

A simple to use and light-weight React validator component.

RepoCompare project screenshot



With Repocompare you can quickly and easily search and compare Github repositories on stars, forks, issues and subscribers.

Greek in Tech project screenshot

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Greek in Techclose

A single-page application (SPA) that displays greek words we use in technology. Check out how many they are!


Knowledge sharing

I ️️❤️ being a mentor, teacher and of course student

Social Hackers Academy

Social Hackers Academy is a Non Profit Organization based in Athens, Greece. It's mission is to educate, find work and help integrate refugees and vulnerable groups.

I'm supporting their cause by teaching JavaScript (and not only). Feel free to support their cause!!!


Code.Hub runs a variety of activities for software engineers and developers such as hackathons and trainings.

My part there is to be one of the React.js instructors. The specific training includes 40 hours of lectures, hands-on exercises and a final project.


I write stuff


My tech blog.

My greek tech blog

Public speaking

Presentations and Talks

Cypress in 10 minutes

Date: 2018, September
Place: Ministry of Testing Athens Meetup #3

A quick introduction and demo on Cypress testing tool. My presentation starts at 32'.

Responsive Web Design and touch devices

Date: 2013, June
Place: JoomlaDay conference, Athens, Greece

The presentation covered aspects of responsive web design on touch devices, touch device problems and solutions, touch events and frameworks, mobile patterns and more.

Pragmatic Responsive Web Design

Date: 2013, March
Place: JoomlaFrappe conference, Athens, Greece

The presentation covered many aspects of responsive web design, like workflow, tools, and tips.

Pragmatic Responsive Web Design

Date: 2012, December
Place: UpNorth web conference, Thessaloniki, Greece

The presentation covered many aspects of responsive web design, like workflow, tools, and tips.

Drupal Tips 'n Tricks

Date: 2010, September
Place: DrupalCamp conference, Athens, Greece

The presentation covered many Drupal CMS related tips and tricks on design and development.

My Abandonware

Projects I no longer support / maintain. Feel free to fork and update them!

Ambrosia theme screenshot

Ambrosia Wordpress theme

Ambrosia Wordpress themeclose

A minimal, modern and adaptive Wordpress theme.

Whitepress theme screenshot

Whitepress Wordpress theme

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An accessible, super clean, minimalistic Wordpress theme.


nwrapper jQuery plugin

A jQuery plugin that allows you to wrap every n elements (a wrap()-like method on steroids).