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Mariusz Kozłowski

Ruby Developer

5 years of experience

● Available
Mariusz Kozłowski
About me

A few words about myself

Ruby on Rails developer with over four years of experience in RoR projects. I started my journey with programming in 2021 and from the beginning it was Ruby language with RubyOnRails framework. I entered the programming environment with 4 years of sales experience which helps me a lot with communication, understanding the customer's needs and finding solutions to meet them using the right tools with a logical approach.

Technical skills

Tech stack

Backend

Ruby Ruby on Rails RSpec FactoryBot Capybara Devise ActiveAdmin Rubocop Redis Sidekiq Avo

Frontend

JavaScript Stimulus HTML HAML CSS SCSS Bootstrap Bulma Tailwind TurboStream TurboFrame SwiperJs ActsAsList StimulusReflex

Database

SQL with PostgreSQL

Other

GitHub Git Dokku Docker Capistrano Cypress FFaker Kamal

Languages

English (Advanced) Polish (Native)
Education

Schools & universities

2012 – 2016

Prof. Janusz Groszkowski Electrical School Complex in Białystok

Electrician

2016 – 2018

Extramural high school Cosinus in Bialystok

Experience

Projects & experience

Course App Guitar Store

2021-10 – 2022

First app created from scratch, with features added step by step next to a course.

Technologies

Ruby on Rails RSpec PostgreSQL Git Bootstrap Devise

Responsibilities

  • E-commerce functionality implementation
  • Product catalog management
  • Frontend based on Bootstrap

Course App Recipes

2021-10 – 2022

Second app created next to a course from a scratch, recipe management application.

Technologies

Ruby on Rails RSpec PostgreSQL Git Bulma Devise

Responsibilities

  • Authorization & authentication with Devise
  • Role-based access control (admin/user)
  • User profile and avatar management with Gravatar
  • Badge system based on number of created recipes

JLL

2023-12 – 2026-04

Internal System for Real Estate market analysis company.

Technologies

PostgreSQL Git Ruby on Rails Haml RSpec SimpleXlsx RubyXL Roo CoffeeScript Ajax PaperClip PaperTrail Bootstrap Sidekiq Sidekiq-Batch

Responsibilities

  • Creating features on backend.
  • Creating features on frontend.
  • Debugging.
  • Participation in discussing and deciding on the features to be introduced.
  • Implementation, maintenance, and development of the application's main data gateway by asynch import xlsx and csv files over 400k rows.
  • Validation asynch jobs and updates them statuses with email notifications about progress of those processes in backround.
  • Generation Xlsx reports.

Kerno

2022-09 – 2023-12

Web application designed to configure different sets of products (doors) and sell them.

Technologies

Git PostgreSQL Ruby on Rails RSpec Cypress Haml Dokku Tailwind Hotwire (Turbo, Stimulus) StimulusReflex ViewComponent dry-rb (dry-effects, dry-validation) Pundit Shrine CSV I18n WickedPdf

Responsibilities

  • Creating features on the backend
  • Creating features on the frontend
  • Debugging
  • Lead junior developer working under the supervision of a senior developer.
  • Build Admin Panel without framework to manage: users, companies, companies branches, dictionaries, product models, orders, offers and connect wizard to config product models
  • Seller Panel to config in wizard multi-positional offers with products based on models configured in Admin wizard.
  • Multipositional offers with dynamic pricing.
  • Dynamic schema draw product in wizard based on inserted dimensions of product.

ZXD

2022-05 – 2022-06

Application for martial arts schools.

Technologies

Ruby on Rails Capybara PostgreSQL Git Haml

Responsibilities

  • Creating features from backend
  • Debugging
  • Giving roles with permissions to specific user type to manage students and their exams, levels, payments, creating school and signing students

Brave Kids

2022-04 – 2022-06

CMS web application designed for children's association sharing their culture.

Technologies

Ruby on Rails RSpec Capybara Cypress PostgreSQL Git Haml Dokku Capistrano Docker Bootstrap JavaScript

Responsibilities

  • Creating features from backend to final view in frontend
  • Unit test with RSpec
  • Integration and e2e tests with Capybara and Cypress
  • Deploy on staging and production
  • Debugging
  • Auto Scrolls using Swiper
  • Rebuild the whole admin panel with bootstrap
  • Gallery section with dynamic switching between galleries
  • Subscription to newsletter with Mailchimp
  • Sending contact form on email
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