Vasilis Kortsimelidis, Developer in London, United Kingdom
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Vasilis Kortsimelidis

Verified Expert  in Engineering

Front-end Developer

Location
London, United Kingdom
Toptal Member Since
October 4, 2017

Vasilis is a front-end expert who specializes in React development. He strives to provide the best user experience through pixel-perfect, accessible, and fast user interfaces. He has worked at a startup, digital agencies, and ASOS, a company with a £4 billion revenue and millions of page views per hour. Vasilis is a proficient developer who can work effectively with other developers, designers, and product managers while mentoring others.

Portfolio

ASOS
React, JavaScript, jQuery, CSS, HTML, UI Development, Git, Node.js, Jest, Redux...
Hopster
HTML, Sass, JavaScript, Redux, React, UI Development, Bootstrap, Git...
ATCOM
JavaScript, jQuery, CSS, HTML, UI Development, Bootstrap...

Experience

Availability

Part-time

Preferred Environment

GitKraken, Visual Studio Code (VS Code), MacOS, React, JavaScript, HTML, CSS

The most amazing...

...achievement I've accomplished was leading the front-end development of ASOS' customer care pages, reducing customer service calls and lowering costs.

Work Experience

Senior Web Engineer

2017 - PRESENT
ASOS
  • Developed web apps like Model Scout that helped streamline the process of hiring models and reduce costs while working on ASOS' content platform team, one of Europe's largest eCommerce companies.
  • Developed the MVP and contributed to the creation of Collusion.com, which increased brand awareness.
  • Led the front-end team that developed ASOS' new customer care pages, reducing customer service calls and costs.
  • Ran a React workshop that helped junior and mid-level web engineers learn the library's basics and how to test components.
  • Built the RSFT (Right Site First Time modal) that helped users redirect to the correct site and increased conversion as a web team member.
Technologies: React, JavaScript, jQuery, CSS, HTML, UI Development, Git, Node.js, Jest, Redux, Cross-browser Compatibility, WCAG 2, Web Accessibility, CSS3, CSS3 Animation, User Interface (UI), DevOps, Web UI, PostCSS, Webpack, New Relic, Visual Studio Code (VS Code), Responsive, Sass, Azure, Immutable.js, Redux Thunk, Interactive UI, Pixel Perfect, HTML5, REST APIs, Tailwind CSS, Accessibility, TypeScript, Front-end, Ajax, QA Testing, Sitecore, Material UI, Playwright, APIs, Full-stack, SQL, Web Development, YAML, Strapi

Front-end Engineer

2016 - 2017
Hopster
  • Developed the application's "My Account" web views with React and Redux to help parents manage their accounts.
  • Created A/B tests that increased user conversion rates in collaboration with the marketing team.
  • Redeveloped the front end of the website to match the new designs pixel-perfectly.
  • Automated end-to-end testing for the website, allowing us to deploy and make changes more confidently using Chimp and Jenkins.
Technologies: HTML, Sass, JavaScript, Redux, React, UI Development, Bootstrap, Git, Cross-browser Compatibility, Jest, Enzyme, CSS3, CSS3 Animation, User Interface (UI), Web UI, Webpack, Google Maps API, Visual Studio Code (VS Code), Responsive, WCAG 2, Immutable.js, Redux Thunk, Interactive UI, Pixel Perfect, HTML5, REST APIs, WordPress, Front-end, Ajax, Photoshop CC, QA Testing, APIs, Google Cloud, Web Development, YAML

Front-end Web Developer

2014 - 2016
ATCOM
  • Developed the front end for the digital agency's clients, including banks and large companies in Greece that receive hundreds of thousands of page views per day.
  • Built the front end of the Aegean Airlines website, which Sitecore awarded as "Site of the Year" and “Best use of Content Management" in Southern Europe. I also made the website WCAG 2.0-compliant to improve keyboard users' experience.
  • Contributed to and developed the front end for many Greek companies' websites, including protothema.gr, novasports.gr, factoryoutlet.gr, ikea.gr, and international companies like Heineken, Vodafone, and Links of London.
Technologies: JavaScript, jQuery, CSS, HTML, UI Development, Bootstrap, Cross-browser Compatibility, Web Accessibility, WCAG 2, Sass, CSS3, CSS3 Animation, User Interface (UI), Web UI, Google Maps API, Visual Studio Code (VS Code), Responsive, Interactive UI, Pixel Perfect, HTML5, Accessibility, Front-end, Ajax, Photoshop CC, QA Testing, Responsive Email Templates, APIs, Web Development, YAML

Front-end Web Developer

2013 - 2014
Plaisio.gr
  • Developed weekly HTML newsletters for approximately 400,000 subscribers.
  • Improved the user experience of approximately 1,000 active visitors through my improvements to the website.
  • Owned the development of mini-site one-page campaigns that helped promote seasonal offers and increase sales for the company.
Technologies: jQuery, CSS, HTML, UI Development, Cross-browser Compatibility, HTML Email, CSS3, CSS3 Animation, User Interface (UI), Web UI, Visual Studio Code (VS Code), Responsive, Interactive UI, Pixel Perfect, HTML5, Front-end, Ajax, Photoshop CC, QA Testing, Responsive Email Templates, Web Development

Web Developer (Intern)

2011 - 2012
EL-Translations
  • Oversaw the front and back end of the company's live site. I also developed new features on the production website to make it easier for users to use our linguistic services.
  • Developed www.el-forces.com, a side project of the company that helps retired army personnel connect and share services.
  • Resolved hardware and software problems of colleagues at the office and sometimes during live seminars the company offered to clients.
Technologies: jQuery, CSS, HTML, UI Development, WordPress, Cross-browser Compatibility, CSS3, CSS3 Animation, User Interface (UI), Web UI, Pixel Perfect, HTML5, Front-end, Ajax, QA Testing, Web Development

ASOS Customer Care Pages

https://www.asos.com/customer-care/
I led a front-end team of two to deliver the customer care pages for the ASOS web team. I managed expectations between different players, such as the SEO, A11Y, and security teams. In addition to reducing the number of calls to customer service agents, this project also reduced ASOS's costs.

Collusion.com

https://www.collusion.com/
In this project, I developed the MVP and then helped create the final website.

With the website's help, the brand increased its awareness of Generation Z–the target audience–and boosted sales for the business.

Aegean Airlines

It was my responsibility to develop the front end for the largest airline company in Greece.

The website was also compliant with WCAG 2.0 guidelines, which helped users, especially those who use keyboards, navigate.

Aegean Airlines won the Sitecore Award for "Best Site of the Year" and "Best Use of Content Management" for this project. More information about this award can be found at http://www.sitecore.com/company/news-events/press-releases/2016/11/aegean-airlines-wins-site-of-the-year/.

Novasports

https://www.novasports.gr/
I developed every HTML template and animations for Novasports.gr, a premium sports service owned by Forthnet Group in Greece, using JavaScript. Originally known as Supersport, the company launched in 1994 as Greece's first premium sports service.

With this newly redesigned portal, the user experience has been improved.

Location Saver | A Personal React Native Project

https://github.com/vaskort/location-saver
This React Native app allows users to save their location and get directions later. The purpose of this project was to learn more about React Native.

It was previously published on Google Play, but the code is still available in the above-mentioned GitHub link.

Find Your Bus Station in London | A Personal AngularJS Project

http://vaskort.com/geocoding-api-web-app/
This app, built in Angular 1, helps users find bus stops in London. The Google Maps API is used to render all the bus stops based on the location input.

The code is available at https://github.com/vaskort/geocoding-api-web-app

Weather App | A Personal React and Redux Project

Using a location input, this React web app renders the weather temperatures for the next few days based on the provided location input.

The code is available at https://github.com/vaskort/weather-app.

Joybird

https://joybird.com/
I developed the pixel-perfect front end for many important website pages, including the navigation and order summary. For that, I effectively engaged with all team members, including developers and designers, and proactively raised issues when they arose. Also, I helped raise and fix front-end inconsistencies across the website, improving overall consistency and user experience and fixing bugs on the desktop, iOS, and Android versions.

Souther Marsh Collection Web Accessibility Improvements

https://southernmarsh.com/
I made the website accessible according to ADA and WCAG guidelines, which improved the user experience, especially for keyboard users, by enhancing and refactoring the JavaScript code whenever necessary while reviewing accessibility requirements.

During my review of web accessibility requirements, I refactored any CSS code to reduce its size, and the Shopify templates were updated or refactored so that I could develop accessibility requirements.

I improved all pages to 100% web accessibility based on the Google Chrome audit.

Suits & Sandals

http://www.suits-sandals.com/
Based on the provided designs, I entirely developed the pixel-perfect front end of the React app. I refactored some React code wherever needed to improve readability and reusability.

As a result of my proactive approach to providing feedback about the designs, the UI across the web application became more consistent.

One-hour User Research for an AI Company

https://octoml.ai/
During a concentrated one-hour user research session for a leading AI company, I provided crucial insights into user interaction and behavior. I gave real-time feedback and intuitive suggestions on their AI application's UI, contributing to possible improvements in its design and usability. Throughout this process, I detected and reported several software bugs within the user testing phase, thereby aiding in immediate quality assurance measures. Additionally, I identified instances of user frustration and promptly suggested ways to enhance the overall user experience. This brief yet focused engagement allowed me to significantly contribute to the refinement of the app's functionality and user satisfaction.

TempoSonus

https://apps.apple.com/gb/app/temposonus/id6450651456?mt=12
A metronome app built using Electron This robust and reliable app provides precise beat tracking essential for practice and performance. It ensures stability and accuracy, initially developed considering the use of Rust with Neon CLI but optimized with JavaScript for the best balance of performance and efficiency. This app is perfect for anyone seeking to perfect their timing and rhythm skills. Available as a paid app on the Mac App Store, with the opportunity to try before you buy. A simple solution for your complex rhythm needs.

Languages

Sass, Ada, CSS, JavaScript, HTML, HTML5, CSS3, TypeScript, YAML, SQL, Jazz, GraphQL

Frameworks

Redux, Bootstrap, Jest, Next.js, Foundation CSS, Tailwind CSS, Material UI, React Native, Angular, Electron

Libraries/APIs

React, jQuery, Node.js, Google Maps API, Immutable.js, REST APIs, Playwright, Liquid, Shopify API

Tools

Git, Redux Thunk, PostCSS, Webpack, Photoshop CC

Paradigms

Responsive, DevOps

Platforms

Visual Studio Code (VS Code), MacOS, New Relic, WordPress, Azure, Shopify, iOS

Other

UI Development, Responsive Email Templates, Cross-browser Compatibility, WCAG 2, Web Accessibility, Axios, Information Technology, Computer Science, Enzyme, HTML Email, CSS3 Animation, Interactive UI, Web UI, Pixel Perfect, Accessibility, Front-end, Ajax, QA Testing, APIs, Full-stack, Web Development, Strapi, Algorithms, Sitecore, Music, Startups, Entrepreneurship, User Interface (UI), OpenAI GPT-3 API

Storage

MongoDB, Google Cloud

2010 - 2016

Diploma in Music

University of West London - London, United Kingdom

2005 - 2011

Bachelor of Science Degree in Information Technology

Technological Education Institute of Thessaloniki - Thessaloniki, Greece

OCTOBER 2018 - OCTOBER 2020

New Relic Certified Performance Pro

New Relic University

OCTOBER 2018 - PRESENT

Design Strategy: Design Thinking for Business Strategy and Entrepreneurship

Coursera

MAY 2018 - PRESENT

Exam 532: Developing Microsoft Azure Solutions

Microsoft

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