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Krzysztof Kamil Piotrowski

Software Engineer

9 years of experience

● Unavailable
Krzysztof Kamil Piotrowski
About me

A few words about myself

I've been a software engineer in 2N.IT since 2017. In the company I've been working on several projects with focus on back-end work for most of the time part, but I also worked on a very front-end focused project. I am very interested in most modern programming technologies and languages and will eagerly take on new challenges in all fields related to those subjects. I spend a lot of extra time in work helping the less experienced in their projects, doing code reviews and pair programming while working full time on my current professional projects. I contribute to open source in Hanami and Dry-rb projects

Technical skills

Tech stack

Backend

Ruby on Rails (8 years) Hanami Trailblazer Postgres MySql Elasticsearch TDD OOP DDD JSON/XML DRY gems REST/JSON/GraphQL/RPC APIs RSpec MiniTest Roda Sequel CQRS EventSourcing RailsEventStore RabbitMQ Pure ruby codebases Basics of C# (for Unity) and C++ Kotlin basic skill GDscript Crystal programming language (with Lucky web framework) Elixir Eventide dry-rb

Frontend

JavaScript (8 years) Vue.js SCSS/SASS/HTML5/CSS3 Stimulus Hotwire/Turbo TailwindCSS Elm (beginner) BulmaCSS and some other CSS frameworks Github View components

Database

PostgreSQL MySQL

Other

Nvim Sublime Atom RubyMine CLion Emacs Git CircleCI Cypress Docker Coolify Heroku View Component Dry-rb AWS/Kubernetes Windsurf plugin for RubyMine with Claude AI

Languages

English (C1) Norwegian (A1) Polish (Native)
Personality & work style

Who I am and how I work

Personality traits

  • Gathering requirements for client
  • Suggesting solutions (both technical and functional)
  • Communicating with other tech-teams
  • Eager to learn
  • Enthusiastic about programming - started learning on my own with no previous experience/education
  • Patient and hard-working
  • Open Source contributor (hanami, dry-rb, rom-rb)
Education

Schools & universities

2010 – 2013

X High School name. Komisji Edukacji Narodowej, Białystok

2013 – 2017

Białystok Law University

National Security Criminal Law & Policy Studies

Experience

Projects & experience

NAU

Internal system for insurance company for calculations, handling money flows, insurance information, marketing, selling products, and generating reports.

Technologies

RoR 3.5, 4.2 jQuery RSpec Sidekiq Haml Sass Git PostgreSQL Capistrano CircleCI ElasticSearch CoffeeScript Capybara Grape API

Responsibilities

  • Designing new features
  • Developing new features, maintaining existing ones
  • Fixing performance issues
  • Code reviewing
  • Contact with client
  • Refactoring old features/underperforming parts of the system
  • Communication with IT teams from external projects
  • Fixing database issues on production environment

Shooting Range app

App for shooting ranges in Poland for administrative use: registering shooting ranges, tournaments, contestants, and results.

Technologies

RoR 5.1, 5.2 jQuery RSpec Sidekiq Haml Sass Git PostgreSQL Capistrano CoffeeScript Capybara

Responsibilities

  • Designing and developing new features
  • Code reviewing
  • Setting application up for first deployment

Showfields

Cloud-based start-up with diverse responsibilities: front-end for admin side, DevOps, GraphQL API, and data-gathering microservice.

Technologies

RoR 5.1 to 6.0.1 jQuery RSpec Sidekiq Haml Sass Git PostgreSQL MySQL Rack GraphQL Trailblazer Stripe Spree Mailchimp Mailgun AWS Docker Kubernetes

Responsibilities

  • Creating, developing and maintaining a stand-alone data gathering microservice
  • Code reviewing
  • Working on the main RoR application with Trailblazer and GraphQL
  • Maintaining DevOps side of both apps
  • Communication with the Front-end team
  • Working with Docker, AWS, Kubernetes

ReDent

Legacy RoR application refactoring: upgrading features, fixing bugs, updating to good-practices and newer Ruby and Rails versions.

Responsibilities

  • Bug fixing
  • Code reviewing
  • Code update

[NDA]

Monolith RoR application with Vue.js frontend to replace an old client app and built as SaaS.

Technologies

Vue.js Ruby on Rails Heroku

Responsibilities

  • Creating a new app based on designs with accuracy to them
  • Coming up with solutions to unforeseen problems
  • Code reviewing
  • Testing features from another dev
  • Working with Heroku

[NDA]

Rails engine for connecting to SAP APIs with Grape REST API and OAuth authorization.

Technologies

Grape OAuth Sequent Sidekiq Faraday

Responsibilities

  • Working with a newly created rails engine
  • Working with SAP API
  • Creating REST API with OAuth
  • Working with Sequent, Sidekiq, Faraday, and basic Rails services architecture

[NDA]

New version of a legacy Rails 3 app rebuilt as REST API using JSONAPI standard.

Technologies

JSONAPI Grape DRY gems

Responsibilities

  • Choosing technology stack for the backend API and admin panel, implementing it
  • Tests optimization

[NDA]

Frontend-focused project that was unfinished and taken over, including fixing backend processes and adding payment integration.

Technologies

View Components Stimulus Cypress

Responsibilities

  • Fixing bugs adding new features according to UX designs
  • Tests optimization

[NDA]

Legacy app from 2011 with redesigned version not yet production-ready. Backend handled React frontend while keeping legacy system working.

Technologies

Elasticsearch Docker Nomad Terraform

Responsibilities

  • Elasticsearch
  • Backend REST API
  • Working closely with frontend on new features
  • A lot of refactoring on the backend side
  • Bug fixes

[NDA]

Long-standing startup with custom TurboStream for live EventSourcing page updates from async Ruby processes.

Technologies

Hotwire TurboStream Elasticsearch EventSourcing

Responsibilities

  • Custom Turbo Stream solutions
  • Updating the backend and frontend tech stacks
  • Introducing new Frontend technologies
  • Working closely with design UI team
  • A lot of refactoring on the backend and frontend side
  • Event Sourcing
  • Lots of updates and reworks done to legacy code and features

Wawruk

New project with 2-4 developers where I did base architecture, set up CI/CD, lead weekly calls, and provided code review and pair programming.

Technologies

View Component Dry-rb Libraries Hotwire Ruby on Rails 7 RSpec TailwindCSS Dokku Docker

Responsibilities

  • Providing code architecture and bases for main development processes
  • Keeping watch on all pull requests, setting up CI/CD
  • Code review and pair programming
  • Leading weekly calls and retro meetings

[NDA]

Project inherited after multiple teams with gradual frontend refactoring from Vue and Rails.

Technologies

Vue (v2) Ruby on Rails Braintree FedEx Easypost Elasticsearch Bootstrap

Responsibilities

  • Integration with FedEx and Easypost
  • Assisting with Braintree integration
  • Frontend work (doing it myself and helping others)

[NDA]

Smaller project where I served as mentoring help and project manager for a junior backend developer.

Technologies

Strapi node.js REST API Ruby on Rails Heroku

Responsibilities

  • Helping to solve bugs or code design solutions
  • Updating the client about the state of the app
  • Resolving communication issues

PSBK

Government project (.gov site) with strict security and hosting requirements. Medical field application built with limited team and time.

Technologies

Hotwire Ruby on Rails TailwindCSS Javascript Docker SpinaCMS

Responsibilities

  • Participating in pre-project meetings to clear doubts about scope
  • Working closely with designer and client on UX
  • Backend development and DevOps
  • Acting as project manager, lead developer and devops

LocalCaddie

MVP for a golfing and tourism application, aimed at automating manual processes for government funding demo.

Technologies

Hotwire Ruby on Rails TailwindCSS Javascript

Responsibilities

  • Specifying scope of application with client
  • Development with team of junior dev and QA
  • Creating and maintaining the server
  • Acting as PM and lead developer

FilmsOn / srefs.co

Two projects for one client heavily based on AI features including picture embeddings, vectors, and ChatGPT integration.

Technologies

Hotwire Ruby on Rails Stripe Javascript TailwindCSS

Responsibilities

  • Working on UI and features related to picture embeddings and vectors
  • ChatGPT integration features
  • Stripe payment integration
  • Authorization layer
  • Styling, video handling

JobValley

Large-scale Germany-based flexible job market platform. Working on staffing and searching branches with ~100 microservices.

Technologies

Ruby on Rails Javascript TailwindCSS VueJS RabbitMQ Elasticsearch PostgreSQL CQRS EventSourcing GraphQL AMQP

Responsibilities

  • Fixing errors with pre-existing systems, refactoring them
  • Speeding up queries and specs in the a complex search service
  • Building new features, refactoring old ones
  • Tech lead engineer for team
  • System design
  • PRDs, feature design and general system architecture
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