Alex

Web developer since 1998. He had met Ruby 12 years later while using Sinatra and Ruby on Rails. Madcap for algorithms. Linux administrator and Open Source ideology evangelist. In free time he explores the secrets of machine learning.

It seems that perfection is attained not when there is nothing more to add, but when there is nothing more to remove.

Antoine de Saint Exupéry

Skills

Backend &Frontend Development Deployment Teamwork Leadership Refactoring TDD Agile Team Building Linux Server Administration Remote Work Product Development

Global JSON Invoicing Standard

An open-source project written in Go, standardizing global electronic invoicing with JSON. It simplifies document creation, ensures compliance with local regulations, and fosters seamless electronic business communication. With a JSON Schema, library, and global tax database, GOBL streamlines the invoicing process for developers. The project emphasizes a practical and standardized approach to electronic business document exchange.

Major contributions

  • XRechnung standard validator on CI
  • Assisting with JSON to XRechnung converter implementation

E-commerce platform for ordering drinks with fast delivery (up to 3 hours) in an eco-friendly way. Service is available to individuals and businesses. From ordering to delivery to picking up empty bottles and reordering, the entire supply chain is supported. Frontend application in Next.js and onion architecture under the hood. Microservices built on Sinatra and powered by Apache Kafka.

Major contributions

  • Development in Next.js
  • Optimize end-to-end testing for CI
  • Custom automated process improvement
  • TMS Order Monitoring service
  • Development in Ruby
  • Eliminate flaky tests
  • Bugs resolving
  • Internal CLI tool development

Global learning platform offering online courses from universities worldwide. Over 19 million users, thousands of courses in dozens of industries. Partners (universities, organizations, industry partners, and government partners) create different types of courses in the app. These include MOOCs (Massive Open Online Courses), ExpertTrack, microcredentials, and degrees. Technologically, the application is a Rails monolith with a React frontend.

Major contributions

  • Development in Ruby on Rails
  • Reusable workflows in the CI pipeline
  • Rich Text Editor in Course Creator
  • Bulk revocation for organisation memberships
  • Support for partners in setting up SAML SSO
  • Maintain and develop integration with LTI
  • Expert Track in Learning Manager
  • Strong password enforcement feature
  • API endpoint improvements
  • Flaky tests reduction
  • Bugs resolving

Management business with no paperwork. Customer service, create invoices, order management. All in one place, easy-to-use and painless. Available API in standard JSON API (in progress).

Major contributions

  • Development in Ruby on Rails
  • Architecture design
  • Code refactoring and optimization
  • UX development
  • Bugs resolving
  • Building service to SAF-T
  • Deployment to production
  • Migration from Heroku to another platform

This is our company website. It shouldn't be complicated. The task of this site is to show what and how we do. We work on it in our free time. The project is public and anyone can look at the code.

Major contributions

  • Development in Ruby on Rails
  • Deployment to production
  • Code refactoring and optimization
  • Migration of app between platforms
  • Architecture design
  • UX development
  • Upgrade Rails and Ruby version
  • Code quality process automation
  • Design of application data structure

Major contributions

  • Configuration and administration
  • Copywriting

Application supporting design hand-made ceramic tiles. Users can choose the shapes, patterns and colors. Ordering process is a multi-step and requires an individual valuation, because the tiles are manufactured by hand.

Major contributions

  • Development in Ruby on Rails
  • Bugs resolving
  • Deployment to production
  • Migration to other platforms
  • Ruby gems dependency reduction

SelectHub

Platform for business to evaluate and acquire the software products. It allows comparison of different IT solutions depending on customer needs. Software vendors give access to the database of leads.

Major contributions

  • Backend development in Ruby on Rails 3.2
  • Frontend development (Backbone.js, Marionette)
  • Bugs resolving
  • Code refactoring

hitdea
based on microservices

Collaborative web-based platform for idea management. It allows to empower people to gather ideas but also process them in a creative, productive and simple way. Based on the methodology CPS 6.1 (Creative Problem Solving).

Major contributions

  • Backend development in Ruby on Rails 4.2
  • Project management
  • SOA design &development
  • Database design
  • UX development
  • Deployment to production
  • Bash scripts to automate workflow
  • Code refactoring
  • Bugs resolving
  • Taking care of software update (Ruby, Rails, gems)
  • Assistance to choosing of technology
  • Data migration from MySQL to PostgreSQL

advertising app

Contextual advertising management. It uses API of linguistic analysis application and allows to define target group.

Major contributions

  • Ruby on Rails development
  • Architecture design
  • Code refactoring
  • Production deployment

linguistic analysis

Linguistic analysis system is used for word processing and automatic category detection. The application can also detect the language of the text. The database contains over 6 million words in Polish and English. The system has a learning mode with a teacher and the categorization is based on statistical methods. Application provides an external API.

Major contributions

  • Backend development in Ruby on Rails
  • Database design architecture
  • Code refactoring
  • Upgrade Ruby and Rails
  • Testing and production deployment
  • Development &production environment setup (MySQL, Solr)

wordmaker

Game of words based on English and Polish languages. Create as many different words as possible from randomly selected letters. Word verification is based on the external API linguistic analysis.

Major contributions

  • Architecture and implementation of most of application the functionality
  • Ruby on Rails development and deployment
  • Extraction of generic functionality to gems

20 questions game

Logic game which learns with every play. In the game you have to answer questions asked by the AI and it will try to guess what were you thinking about.

Major contributions

  • Project management
  • Deployment to production


Backend development


  • Ruby
  • Ruby on Rails
  • Sinatra
  • Jekyll
  • JRuby
  • TruffleRuby
  • Go

Databases


  • PostgreSQL
  • MySQL
  • SQLite
  • Redis

Frontend development


  • JavaScript
  • TypeScript
  • React
  • Next.js
  • CoffeeScript
  • ®Ember.js
  • Backbone.js
  • Marionette.js

Web technologies


  • Less
  • Sass
  • HTML Abstraction Markup Language
  • Slim Template Language
  • Scalable Vector Graphics
  • HTML5
  • CSS3
  • BootstrapBootstrap
  • Foundation Framework
  • Markdown

Testing


  • RSpec
  • minitest
  • Playwright
  • Selenium WebDriver
  • Selenium IDE
  • Shoulda Matchers
  • Cuprite - Headless Chrome driver for Capybara
  • Ferrum - high-level API to control Chrome in Ruby

Tools


  • Git
  • GitHub
  • Sidekiq
  • docker
  • Terraform

Search engine


  • Elasticsearch
  • Apache Solr
  • OpenSearch

Operating systems


  • GNU/Linux
  • Ubuntu
  • debian
  • Linux Mint
  • openSUSE
  • SSSSSlackware
  • Slax
  • Alpine

Cloud Computing


  • Heroku
  • DigitalOcean
  • Amazon Web Services
  • Google Cloud
  • Fly.io

Mathematical software


  • MATLAB

Project management software


  • Trello
  • Taiga

Linters &code formatters


  • RuboCop
  • ESLint
  • Prettier
  • Stylelint

CI (Continuous Integration)


  • GitHub Actions
  • Jenkins
  • Hound CI
  • Travis CI