Marcin S.

About Me

Marcin is a Senior Software Engineer with 15+ years of verified success in developing creative and effective business solutions using Ruby, Ruby on Rails, JRuby, Git, UNIX, Node.js, and design patterns. He is keen on learning new technologies and working well either in a team or solo, committed to developing products that exceed client and end-user expectations.

Backend

DevOps

Other

Work history

UpStack
UpStack
Senior RoR Engineer
2018 - Present (7 years)
Remote
  • Creating and developing innovative software solutions for clients across a broad range of industries.

  • Participating in scrums consisting of cross-functional teams, both software and hardware.

  • Ensuring that features are being delivered efficiently and on time.

YND Consult
YND Consult
Back-end Developer
2018 - 2018
Remote
  • Maintained and developed new features for Dine+Go (dineandgo.com) mobile application’s back end with Ruby and Elixir.

  • Kept backward compatibility with the app's earlier version.

  • Added new features according to schedule.

Freelance
Freelance
Ruby on Rails Developer
2013 - Present (12 years)
Remote
  • Managing comprehensive projects for clients across a broad range of industries.

  • Implemented a system for processing big amounts of items with sophisticated status flows.

  • Built a JRuby web tool for PayPal's HR managers to create custom PDF documents.

  • Built Clarus Warehouse Management System from scratch and took it to the point where it was successfully deployed and used by clients.

Tix.nl
Tix.nl
Ruby on Rails Developer
2013 - 2014 (1 year)
Remote
  • Led the front- and back-end performance benchmarking and optimization and implemented a fully automated CI process.

  • Conducted weekly demos for the CEO and actively participated in sprints planning, promoting the company's Scrum philosophy.

  • Created integration tests with Capybara covering new functionalities and developed a Ruby on Rails application using Java for the back end.

Groupe SII
Groupe SII
Software Engineer
2012 - 2013 (1 year)
Remote
  • Developed custom Redmine extensions and improved functionalities.

  • Created a Symfony-based eCommerce project for one of the biggest Polish price comparison sites.

  • Built an internal SOAP API and tested code with PHPUnit and RSpec.

Goldenline
Goldenline
Back-end Developer
2011 - 2012 (1 year)
Warsaw, Poland
  • Implemented new functionalities for the company website including new client profiles, tested with PHPUnit and Selenium, and created an internal API with the Silex framework.

  • Optimized performance using Memcached, Membase, and the Sphinx Search Server.

  • Improved core site functionality including a complex candidate search engine for recruiters.

Freelance
Freelance
Software Developer
2008 - 2011 (3 years)
Remote
  • Audited and improved the performance and security of various websites.

  • Designed and developed various CRM applications.

  • Developed websites with PHP and Rails.

Showcase

Ruby on Rails Developer - Clarus WMS
Ruby on Rails Developer - Clarus WMS
  • Implemented a system for processing large amounts of data with sophisticated status flows.

  • Optimized the time cards of physical workers in warehouses using graph theory and advanced programming techniques.

  • Implemented a custom login service daemon for FTP Server using Clarus Devise accounts.

Ruby on Rails Developer - BPP
Ruby on Rails Developer - BPP
  • Developed a comprehensive online system for BPP University.

  • Extracted and reused components from the codebase to create external gems.

  • Utilized Rails and Ember.js technologies.

Ruby on Rails Developer - Tito
Ruby on Rails Developer - Tito
  • Migrated a Rails 4 monolith to a Rails 5 architecture.

  • Implemented a loosely coupled system for Tito, a B2B event software.

  • The transition is based on a redesign of the Rails architecture.