Daniel Rosenwasser
Senior Program Manager at Microsoft
Seattle, Washington, United States
Summary
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Top expert inFull-Stack JavaScript Development
Daniel Rosenwasser is a Senior Program Manager at Microsoft with 13 years of experience shaping the TypeScript language and its ecosystem from compiler internals to developer tooling. As Principal Product Manager of TypeScript on GitHub and a long-time contributor to high-profile repos like microsoft/TypeScript and vscode, he blends language design, specification work (TC39 proposals), and hands-on implementation across front-end and back-end code. He has deep expertise porting compilers (including a native Go port), refining grammar/spec documents (optional chaining, type annotations), and improving editor integrations and runtime helpers. Comfortable switching between low-level optimization and product-facing features, he also drives experimentation and A/B testing in developer tools. Based in Seattle, Daniel pairs pragmatic engineering with documentation and tooling improvements that make advanced language features accessible to millions of developers.
13 years of coding experience
3 years of employment as a software developer
Rochester Institute of TechnologyBronx High School of Science
Stackoverflow
22,423reputation
1.3mreached
119answers
10questions
npm
top-5%
webpack
top-5%
generics
top-5%
rxjs
top-5%
typescript
top-1%
jsx
top-5%
Github Skills (69)
parser10
website-development10
github10
python10
testing10
typescript-definitions10
type-system10
specification10
optional-chaining10
optimization10
javascript10
git-repository10
abstract-interpretation10
go-testing10
bundle10
Programming languages (30)
Github contributions (5)
microsoft/tslib
Jun 2016 - Oct 2022
Runtime library for TypeScript helpers.
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:28 releases, 6 reviews, 60 commits in 6 years 5 months
Contributions summary:Daniel's contributions centered on enhancing the `tslib` runtime library. They focused on adding and updating helper functions, specifically `__makeTemplateObject`, that are crucial for modern JavaScript development, especially concerning template literals. Their work included modifying both `tslib.js` and `tslib.es6.js` files, and integrating these changes across different parts of the library. Furthermore, the user was involved in license modifications and refactoring for improved code maintainability.
typescripttypescript-helpersbundle
microsoft/TypeScript-Sublime-Plugin
Mar 2015 - Aug 2022
IO wrapper around TypeScript language services, allowing for easy consumption by editor plugins
Role in this project:Full-stack Developer
Full-stack DeveloperContributions:24 releases, 105 commits, 44 PRs in 7 years 7 months
Contributions summary:Daniel's commits focused on updating the TypeScript plugin for the Sublime Text editor. This involved upgrading the TypeScript versions used by the plugin across multiple commits. The commits also included the implementation of a 'go to type definition' feature, demonstrating work on code navigation and integration with TypeScript language services. These changes primarily affected the plugin's core functionality and its interaction with the TypeScript language server.
typescript
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