Piotr Rybarczyk
Staff Software Engineer at Fresha
Warsaw, Masovian Voivodeship, Poland
Summary
👤
Senior🎓
Top SchoolPiotr Rybarczyk is a Staff Software Engineer based in Warsaw with 10 years of experience designing and scaling backend platforms, especially in Ruby and Elixir. He has deep expertise in event-driven microservices, Kafka tooling, and BEAM internals, and has driven performance improvements such as a tenfold speedup on a 3k RPS availability service. At Fresha he moved from hands-on backend work to technical leadership of data engineering—building Kafka pipelines, Snowflake infrastructure, and custom Elixir libraries—while continuing to mentor teams and run Event Storming workshops. He also contributes to open-source e-commerce (Spree) and has a history of migrating complex platforms and optimizing Postgres/PostGIS search. Comfortable bridging product and infrastructure, Piotr brings a pragmatic focus on observability, real-time data, and maintainable systems.
10 years of coding experience
8 years of employment as a software developer
Mathematics, Mathematics at LO nr XXXVII im. J. DąbrowskiegoBachelor's degree Geodesy And Cartography - Extramural Studies, Bachelor's degree Geodesy And Cartography - Extramural Studies at Warsaw University of TechnologyBachelor's degree Computer Science, Bachelor's degree Computer Science at Warsaw School of Computer Science
Polish, English
Stackoverflow
1,025reputation
35kreached
52answers
1question
Github Skills (19)
spreed10
ruby-rails10
back-end-development10
ecommerce10
rails10
ruby10
spree10
backend10
ruby-on-rails10
apidoc9
api9
postgresql8
storefront8
activerecord6
rspec6
Programming languages (9)
Github contributions (5)
spree/spree
Apr 2016 - Oct 2016
An open source eCommerce platform giving you full control and customizability. Modular and API-first. Multi-vendor, multi-tenant, multi-store, multi-currency, multi-language. Built using Ruby on Rails. Developed by @vendo-dev
Role in this project:
Back-end Developer
Back-end DeveloperContributions:18 commits, 9 PRs, 1 comment in 6 months
Contributions summary:Piotr primarily contributed to the backend functionality of the Spree e-commerce platform. Their work included refactoring code by removing unused actions, updating admin panel breadcrumb navigation for several sections (e.g., store credit categories, stock movements, stock transfers, users, and stock locations), and introducing changes to support the admin panel management for Reimbursement Types. Further contributions involved updating the project's dependencies, including changes related to the VersionCake library.
multi-sourceecommercemulti-languagespreecommerceshopware
Argonus/kafka_ex
Feb 2021 - Mar 2024
Kafka client library for Elixir
Contributions:7 PRs, 135 pushes, 32 branches in 3 years 1 month
client-librarykafkakafka-clientelixir
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