Sergey Kozhin
Senior Software Developer at Netsoft Holdings Limited
Valencia, Valencian Community, Spain
Summary
👤
Senior🎓
Top SchoolSergey Kozhin is a senior software developer with over 20 years in IT and 16 years of hands-on professional experience building and scaling SaaS web applications. A Ruby on Rails specialist since Rails 1, he architects full-stack solutions and has led multiple Rails upgrades, CI implementations, and integrations across PostgreSQL, Redis and AWS. He combines backend expertise with frontend work (Vue.js, Stimulus) and a history of improving reliability and deliverability—examples include reducing bounced SES emails and stabilizing high-traffic e-commerce flows. Sergey contributes to open-source web framework internals (notably improvements to cookie and session handling in the Lucky Crystal framework), showing deep HTTP and framework-level knowledge beyond typical application work. Based in Valencia, Spain, he pairs a strong technical background and master's training with practical product-minded delivery for regulated timelines. Colleagues rely on him for pragmatic architecture decisions that balance speed, robustness and operational cost.
16 years of coding experience
21 years of employment as a software developer
Master's degree, Data Processing and Computer-Aided Management (CAM) Systems, A, Master's degree, Data Processing and Computer-Aided Management (CAM) Systems, A at Volgograd State Technical University
English, Russian
Stackoverflow
33reputation
11kreached
6answers
0questions
Github Skills (15)
web-framework10
http-cookie10
crystal-lang10
webpages10
session-management10
web-content10
error-handling9
turbolinks8
testing8
schema-org6
google-places-api6
google-plus6
geoip6
ruby6
ruby-on-rails6
Programming languages (10)
Github contributions (5)
luckyframework/lucky
Apr 2019 - Jan 2022
A full-featured Crystal web framework that catches bugs for you, runs incredibly fast, and helps you write code that lasts.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:11 commits, 12 PRs, 22 comments in 2 years 10 months
Contributions summary:Sergey primarily contributed to the Lucky framework's core functionalities, specifically focusing on cookie handling and session management. They implemented features such as writing only updated cookies to the response and refactored the `CookieOverflow` exception handling to occur during cookie setting. Additionally, the user improved AJAX form handling and made the deletion of non-existent cookies not fail. Their work shows expertise in web framework internals and HTTP protocol implementation.
full-featuredcrystallucky-frameworkframeworkruns
skojin/counter_cache_with_conditions
Jan 2010 - Mar 2017
Contributions:42 commits, 1 PR, 16 pushes in 7 years 3 months
railscounter-cacheabilityrubyspecify
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