Kamil Grzegorczyk, Developer in Vienna, Austria

Kamil Grzegorczyk

Performance Analysis Developer

Vienna, Austria
Toptal Member Since
June 26, 2018

Kamil is a seasoned web developer with over 15 years of experience who’s collaborated with a number of companies and individuals from all over the world. He’s worked on wide range of projects from small websites to huge projects serving millions of users per day. Kamil has broad in-depth experience and pays a great deal of attention to quality as well as being extremely dedicated to every task that he undertakes.

Kamil is available for hire
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Luckie & Company
Jenkins, Linux Administration, Node.js, WordPress, CSS, JavaScript, PHP
Jenkins, Preact, React, Linux Administration, Node.js, WordPress, CSS...
DevOps, Node.js, React, JavaScript, PHP, WordPress


Vienna, Austria



Preferred Environment

PhpStorm, MacOS

The most amazing...

...project I've worked on was a huge media project serving 1.5 million users per day. I worked there full-time for three years.

Work Experience

2013 - PRESENT

Lead Developer (Contractor)

Luckie & Company
  • Led the development of mid-scale WordPress-based websites.
  • Designed and developed the project architecture, deployment, and development strategies.
  • Performed very detailed product performance analysis and optimization.
  • Handled the Linux server administration.
  • Configured and managed various build servers like Jenkins.
  • Set the team's code style, development processes, and branching methodologies.
Technologies: Jenkins, Linux Administration, Node.js, WordPress, CSS, JavaScript, PHP
2006 - PRESENT

Owner | Lead Developer

  • Led multiple simultaneous projects with teams consisting of six to eight people.
  • Designed and developed project architecture, deployment, and development strategies (continuous integration, continuous deployment).
  • Performed very detailed product performance analysis and optimization.
  • Developed in various back-end technologies like PHP or Node.js.
  • Built-up the front-end HTML5, CSS3, and JavaScript along with frameworks like jQuery, Backbone.js, Angular, and React.
  • Developed or consulted on and provided analysis for small- to high-scale WordPress-based websites.
  • Managed projects from marketing, negotiations to wireframing, development, and final product.
  • Performed Windows and Linux servers administration.
  • Handled company management (finances, planning, organization, accounting, and human resources).
  • Configured and managed various build servers like Jenkins.
Technologies: Jenkins, Preact, React, Linux Administration, Node.js, WordPress, CSS, JavaScript, PHP
2016 - 2017

Senior Full-stack Developer

  • Mentored junior developers and performed code reviews.
  • Built a WordPress-based company website connected with a trading application written in Node.js.
  • Implemented a performance analysis and defined the long-term strategy and optimizations.
  • Designed and executed build and deployment strategies and continuous development and deployment.
  • Developed using PHP, JavaScript, and CSS.
  • Set up the working environment and technology stack for a team of developers.
  • Designed the development processes, workflow, and introduced scrum basics.
Technologies: DevOps, Node.js, React, JavaScript, PHP, WordPress
2013 - 2016

Senior Front-end Developer

Redact Media
  • Wrote the front-end code for extremely high traffic websites (1.5 million users per day).
  • Built internal admin tools based on Angular.
  • Worked in an Agile-driven (Scrum) environment; the core of the work had a strong focus on website load performance and optimization.
  • Implemented long-term (more than a year) SEO optimizations and advertisement campaigns for maximum user conversion.
  • Researched and made technology and solution choices.
  • Defined the architecture.
  • Implemented unit and functional testing.
  • Developed build process and deployment strategies.
Technologies: Test-driven Development (TDD), AngularJS, Backbone.js, CSS, PHP, JavaScript
2009 - 2009

IT Administrator

Białystok University of Technology
  • Managed 250+ Windows workstations and other devices.
  • Wrote the specifications for and managed the implementation of EU-financed projects.
  • Managed a campus network and its devices.
  • Provided everyday tech support for science and administration employees of the university.
  • Analyzed and repaired hardware failures of the user workstations.
  • Worked with software and hardware vendors in providing the best quality tools for university employees.
Technologies: Azure Active Directory, Windows, MikroTik, Cisco, Linux
2002 - 2006


Freelance Work
  • Worked on various simple and basic web development projects on a freelance basis.
Technologies: PHP, CSS, HTML


US Civil Rights Trail

I was responsible for the full development of this website starting from the server set up, Jenkins build server configuration, and build process.

The project is based on WordPress with Composer in the root of its architecture. I also created a special build process for the theme which uses the newest version of Webpack. The site also heavily relies on Google Maps API.

Catered Bowl

Catered Bowl is a very simple and lightweight WordPress based website. Similar to other websites, it uses a Composer-based architecture and Webpack-based build process. I was also responsible for setting up Jenkins, the build process as well as the server configuration. It also uses a refactored version of a store locator plugin.

Extremely High Traffic Media Website

This project was one of the biggest achievements of my career—an extremely high traffic project serving up to 1.5 million users per day. I worked on it for three years as a senior front-end developer.

My everyday tasks mainly focused on code quality and optimization to achieve the best performance and load times under various conditions. This included building back-end tools supporting the project, some of them were plain PHP/jQuery applications and some of the tools were already written in Angular.

The project was built by an agile team working in a scrum environment. Unfortunately, I am unable to share the link to the project.

OS Library | WordPress Architecture Stack and Starter Theme

My own open-source library used as a starter kit for building optimal, performant WordPress architectures. It uses plenty of best practices and tools which are state of the art in 2018 (for example, Webpack 4).

It focuses on security, ease of configuration of environments, and improved deployments and performance. The main selling point is that it tackles is data separation. It also comes with a starter theme based on Twig. The library was released recently but the most of the code of this library runs on production websites that I've built in the past.


This is my own company website for the projects I made until 2013 (mostly for the sports industry). The website contains plenty of WordPress articles that I authored mostly in 2012-2013 and much of the knowledge, advice, and practices are still applicable even after so many years.

As I stopped working for sports clients, it has not been updated in five years, but it still showcases some of my best work of my professional career.



HTML, JavaScript, CSS, PHP, SQL


jQuery, Preact, React, Google Maps, Backbone.js, Facebook API, Instagram API, Node.js


Git, Webpack, Gulp, Grunt, Jenkins, Adobe Lightroom, Plesk, PhpStorm, Composer, Sketch, Mercurial, Adobe Illustrator, Adobe Photoshop, PM2, Ghost


WordPress, Linux, MacOS, Windows


Performance Analysis, Code Review, Server Administration, System Administration, Linux Administration, Cisco, MikroTik


Refactoring, Pair Programming, Scrum, Agile, DevOps, Test-driven Development (TDD), Object-oriented Programming (OOP)




Azure Active Directory, MySQL, MongoDB


2003 - 2007

Master's Degree in Information Technology in Economics

Bialystok University of Technology - Bialystok, Poland



Certified Scrum Developer (CSD)

Scrum Alliance


Certified ScrumMaster (CSM)

Scrum Alliance