Piotr Kowalski
Principal Software Development Engineer at Freelance
San Francisco, California, United States
Summary
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Senior🎓
Top SchoolPiotr Kowalski is a Principal Software Development Engineer based in San Francisco with 12 years of experience as a freelance developer, specializing in JavaScript, PWAs, IoT and PHP. He blends back-end rigor with front-end polish, contributing to notable open-source projects such as Slim, Joomla CMS, and the Preact-based WMR tool where he improved routing, internationalization, and developer tooling. Piotr has a strong focus on maintainability and documentation—adding timezone-aware DateTime handling to a popular CRON PHP library and improving Phinx migration docs—demonstrating both code-level craftsmanship and developer experience advocacy. Comfortable across full-stack responsibilities, he repeatedly fixes subtle core bugs and refactors framework code to improve stability and testability. Trained in computer science at the University of Wroclaw, he brings a pragmatic, detail-oriented approach to building reliable web and embedded systems.
12 years of coding experience
11 years of employment as a software developer
Magister (Mgr) Informatyka, Magister (Mgr) Informatyka at University of Wroclaw
Stackoverflow
9,205reputation
2.3mreached
84answers
0questions
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Github Skills (47)
database-migrations10
content-management-system10
cms10
debug10
javascript10
url-routing10
mysql10
app-framework10
joomla10
migration10
javascript-objects10
php10
headless-cms10
content-management10
db-migrate10
Programming languages (25)
Github contributions (5)
slimphp/Slim
Jun 2017 - Feb 2021
Slim is a PHP micro framework that helps you quickly write simple yet powerful web applications and APIs.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:13 commits, 11 PRs, 81 comments in 3 years 8 months
Contributions summary:Piotr focused on refactoring and improving the Slim PHP micro-framework's routing capabilities. Their work involved modifying the `RouteCollectorProxy` and `Dispatcher` classes to handle base paths more effectively. Additionally, the user fixed tests related to the `RouteCollectorProxy` and removed unused classes, further contributing to code quality. These changes demonstrate a focus on core framework functionality and maintainability.
micro-frameworkguzzlephp-frameworkslim-frameworksimple-yet-powerful
agentejo/cockpit
Dec 2014 - Feb 2020
Add content management functionality to any site - plug & play / headless / api-first CMS
Role in this project:Full-stack Developer
Full-stack DeveloperContributions:68 commits, 41 PRs, 72 comments in 5 years 3 months
Contributions summary:Piotr contributed to the Cockpit CMS project by addressing asset compilation issues and improving internationalization. They added missing translations and updated the sample language file. Furthermore, the user enhanced the project's functionality by implementing features related to form data emails and geolocation coordinates. The commits also included fixes and improvements to the UI and backend logic.
cmscms-frameworkriotjsapijavascript
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