Marcin Szczepanski
Principal Developer, UI Platform (Frontend Infrastructure)
Sydney, New South Wales, Australia
Summary
🤩
Rockstar🎓
Top SchoolMarcin Szczepanski is a Principal Developer with 14 years of experience building and scaling frontend delivery platforms, currently leading UI Platform (Frontend Infrastructure) at Atlassian from Sydney. He spent 12 years at Atlassian driving shared frontend infrastructure across products like Jira and Bitbucket, with a focus on developer experience, build tooling and reliable delivery. Marcin pairs hands-on engineering with platform-level thinking—contributing to well-known open-source projects such as Parcel where he improved bundling, tracing and lazy compilation, and to FW/1 by hardening error handling and testability. His background spans full-stack and backend automation, early ColdFusion work, and founding a Rails/iOS consultancy, giving him a rare cross-stack perspective on developer tooling and product delivery. Collectedly, he blends pragmatic engineering, open-source impact, and a track record of scaling developer-facing systems in large organisations.
14 years of coding experience
22 years of employment as a software developer
UNSW Sydney
Stackoverflow
802reputation
23kreached
10answers
2questions
Github Skills (24)
javascript10
testing10
s610
bundle10
web-framework10
error-handling10
build-tools10
bundling10
test-automation10
web-content9
webpages9
compiler-compiler9
compiler9
typescripts7
typescript7
Programming languages (11)
Github contributions (5)
framework-one/fw1
Oct 2011 - Jan 2014
FW/1 - Framework One - is a lightweight, convention over configuration, MVC application framework for ColdFusion / CFML.
Role in this project:
Back-end Developer & Test Automation Engineer
Back-end Developer & Test Automation EngineerContributions:54 commits in 2 years 3 months
Contributions summary:Marcin primarily contributed to improving the FW/1 framework's error handling and testing capabilities. They ensured the availability of `request.context` in the `onError` handler and abstracted `writeOutput` calls for better testability. Furthermore, the user implemented initial test cases for the `onError` handler and enhanced the error handling to support early failures, and improved the test suite setup and content.
phpcfmlframeworkmvc-applicationapplication-framework
parcel-bundler/parcel
May 2022 - Dec 2022
The zero configuration build tool for the web. 📦🚀
Role in this project:Full-stack Developer
Full-stack DeveloperContributions:148 reviews, 3 commits, 55 PRs in 6 months
Contributions summary:Marcin primarily focused on improving the Parcel bundler's capabilities and addressing bug fixes. Their contributions include implementing support for glob resolver packages, resolving deep entry point issues, and ensuring the maximum number of listeners for process.stdout accounts for workers. Furthermore, the user worked on adding tracing capabilities, enhancing lazy compilation functionalities, and optimizing the inline requires plugin for improved performance. They also updated the project to migrate to swc_core.
configurationzerocommonjscssjavascript
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