EXCEEDS logo
Exceeds
Mateusz Kadlubowski

PROFILE

Mateusz Kadlubowski

Xeho91 engineered core enhancements for the storybookjs/addon-svelte-csf repository, focusing on type safety, maintainability, and seamless Svelte integration with Storybook. Over several months, they modernized AST utilities, refactored export and meta handling, and improved test coverage to support evolving Storybook APIs. Xeho91 introduced robust TypeScript typing, streamlined CI/CD pipelines, and upgraded build tooling with Vite and Vitest, reducing maintenance risk and improving developer velocity. Their work included SvelteKit scaffolding, advanced code generation, and documentation updates, addressing both legacy and modern workflows. By resolving complex integration issues, Xeho91 enabled more reliable story rendering and simplified contributor onboarding across the ecosystem.

Overall Statistics

Feature vs Bugs

63%Features

Repository Contributions

112Total
Bugs
14
Commits
112
Features
24
Lines of code
12,446
Activity Months7

Work History

May 2025

39 Commits • 9 Features

May 1, 2025

May 2025 performance summary: Delivered core tooling upgrades, CI efficiency improvements, and robust SvelteKit and Storybook ecosystem support. Focused on performance, maintainability, and type safety, enabling faster iterations and more reliable stories across Svelte and Storybook platforms. This work reduces dependency churn, speeds up CI, and provides a scalable foundation for future features.

April 2025

2 Commits • 2 Features

Apr 1, 2025

April 2025 Monthly Summary: Key features delivered, major fixes, impact, and technical accomplishments across two repositories. Key features delivered - biomejs/website: Documentation: Linter Plugin Severity Standardization. Updated the documentation to correct the allowed values for the 'severity' diagnostic and standardize severity levels across languages, ensuring consistency in documentation. Commit: b4839ce1bd84d8ec980d938fc427b6a88086c9fe. Business value: reduces developer confusion and aligns docs with implementation. - storybookjs/addon-svelte-csf: CI and ESLint Configuration Modernization. Migrated ESLint configuration from a JavaScript file to a flat configuration format, updated the CI workflow to use the new ESLint configuration, and installed necessary dependencies. Commit: 6fa176436c5fc8c6458ff9c11053b4bf71b61775. Business value: simplifies configuration, speeds up builds, and improves maintainability. Major bugs fixed - No major bugs fixed were documented for this period. Overall impact and accomplishments - Improved developer experience and consistency across projects by standardizing lint severity documentation and modernizing tooling. - Reduced maintenance overhead through ESLint flat config migration and aligned CI workflows. - Strengthened code quality and onboarding efficiency through clearer docs and streamlined tooling. Technologies/skills demonstrated - Documentation standards and governance for lint rules - ESLint flat configuration and migration - CI/CD workflow modernization and dependency management - Cross-repo coordination and change communication Business value - Faster, more reliable development cycles; lower risk of lint misconfigurations; easier contributor onboarding; improved cross-team collaboration.

March 2025

1 Commits

Mar 1, 2025

March 2025 focused on risk reduction and maintainability for the storybookjs/addon-svelte-csf repository. No new user-facing features were shipped; instead, we stabilized UI behavior by temporarily disabling the save-from-UI workflow and started a targeted refactor of parameter-handling modules to improve clarity and future extensibility. The change is tracked via the commit that disables the UI save feature and acknowledges ongoing work for future re-enablement.

January 2025

9 Commits • 2 Features

Jan 1, 2025

January 2025 monthly summary: Delivered key features and fixes across two repos to improve reliability, developer experience, and documentation for Storybook Svelte users. In storybookjs/addon-svelte-csf, delivered Story Export Tagging and Structure Enhancements, refactoring createNamedExportStory to support object expressions and aligning tests/snapshots with the new story node structure and per-story tags. Also addressed Legacy Story Codemod and Svelte Transformer Bug Fixes, correcting identifier naming in the Svelte AST (children -> template) and updating tests/snapshots, plus Documentation Formatting Correction to revert markdownlint auto-formatting in ERRORS.md. In storybookjs/storybook, improved Svelte docgen robustness across AST versions, removing brittle version-specific logic for Svelte v4, and increased type safety by explicitly importing ESTree AST types, with corresponding test updates. These changes reduce maintenance risk, improve doc generation reliability in Vite-based workflows, and enable better tag-based story discovery for teams.

December 2024

20 Commits • 3 Features

Dec 1, 2024

December 2024: Delivered architectural refinements and enhancements across the Storybook Svelte integration and core compiler, driving developer productivity and code quality. Key features delivered: - storybookjs/addon-svelte-csf: Meta handling modernization and AST utilities, including createASTIdentifier(), API cleanup for plugin integration, restructured export default meta creation (moved to create-appendix.ts), and comprehensive test/snapshot updates. Significant cleanup removed obsolete meta logic and improved error handling. - storybookjs/addon-svelte-csf: Template literals support in legacy codemod and source extraction, with tests and a new TemplateLiterals story to improve migration accuracy. - sveltejs/svelte: Exposed additional AST types and exported the CSS namespace for better API usability and integration.

November 2024

25 Commits • 5 Features

Nov 1, 2024

Month: 2024-11 — Concise delivery across the storybook addon for Svelte CSF with a focus on typing safety, test reliability, and maintainability. Key features delivered include restoring legacy StoryProps typing with template support for Story and templating examples, and introducing asChild for flexible composition. A Transform Parser refactor simplified maintainability and readability. In parallel, dependencies and configuration were modernized (deps, Vitest config, migration docs), while docs were updated to reflect current usage. Major bug fixes targeted test stability, environment compatibility, and import correctness (including file extension handling and svelte-check integration). Overall impact: reduced runtime/import errors, safer contributor workflow, and faster release cycles; technical improvements align with business value by increasing developer velocity and reliability of story rendering and testing in CI. Technologies/skills demonstrated include advanced TypeScript typing strategies, test tooling modernization (Vitest, Vite, happy-dom), build tooling stabilization (Rollup, svelte-check integration), and code quality improvements from targeted reviews and refactors.

October 2024

16 Commits • 3 Features

Oct 1, 2024

October 2024 monthly summary for storybookjs/addon-svelte-csf. Focused on delivering type-safe, API-aligned Svelte CSF enhancements, improving autodocs compatibility, and upgrading tooling to boost reliability and maintainability. The work emphasizes business value: smoother migration to the latest Storybook API, more robust Svelte addon integrations, and stronger developer experience through better tests and docs. Key highlights: - Delivered type-safe Svelte CSF addon updates with API alignment (PlayFunctionContext -> StoryContext, createRawSnippet, tighter Cmp types). - Enhanced autodocs and compatibility for LegacyStory/LegacyTemplate with updated tests and codemods. - Maintained CI stability by addressing legacy integration tests and temporarily quieting non-critical type issues. - Upgraded development tooling and documentation (dependencies, pnpm version, improved docs). Overall impact: - Improved integration reliability with the latest Storybook API, enabling easier adoption for users migrating from legacy CSF. - Increased maintainability and test coverage for the Svelte addon, reducing future maintenance costs and risk. Technologies/skills demonstrated: - TypeScript typings and API refactoring, Storybook architecture changes, autodocs/testing, codemods, and pnpm tooling.

Activity

Loading activity data...

Quality Metrics

Correctness92.4%
Maintainability93.2%
Architecture90.0%
Performance89.4%
AI Usage21.0%

Skills & Technologies

Programming Languages

HTMLJSONJavaScriptMarkdownSvelteTypeScriptYAMLjavascriptmdxsvelte

Technical Skills

API DesignAST ManipulationAST ParsingAddon DevelopmentBrowser AutomationBuild ToolsCI/CDCode CleanupCode CompilationCode FormattingCode GenerationCode MaintenanceCode OrganizationCode RefactoringCode Transformation

Repositories Contributed To

4 repos

Overview of all repositories you've contributed to across your timeline

storybookjs/addon-svelte-csf

Oct 2024 May 2025
7 Months active

Languages Used

JavaScriptSvelteTypeScriptsvelteHTMLMarkdownYAMLjavascript

Technical Skills

CI/CDCode CleanupCode RefactoringCode TransformationComponent DevelopmentDependency Management

storybookjs/storybook

Jan 2025 May 2025
2 Months active

Languages Used

JavaScriptTypeScriptHTMLJSONMarkdownSvelteYAMLmdx

Technical Skills

AST ParsingCode RefactoringDocumentation GenerationPlugin DevelopmentSvelteTypeScript

sveltejs/svelte

Dec 2024 May 2025
2 Months active

Languages Used

JavaScriptTypeScript

Technical Skills

AST ManipulationCompiler DevelopmentJavaScriptTypeScript

biomejs/website

Apr 2025 Apr 2025
1 Month active

Languages Used

Markdown

Technical Skills

Documentation

Generated by Exceeds AIThis report is designed for sharing and indexing