Marshall Roch is a UI Engineer with 15 years of experience building reliable, developer-facing tools and polished front-ends at Meta and across high-profile open-source projects. He blends deep language and systems knowledge—from JavaScript, Ruby, and PHP to OCaml and C—with a human-computer interaction background (BS/MS from Carnegie Mellon) to improve both usability and type safety. His contributions to flagship projects like React, React Native, Flow, Metro, Relay and the Flow VS Code extension show a rare full-stack fluency: shipping UX improvements, refactors, type-system enhancements, and build/devops fixes. Comfortable moving between parser and AST work, bundler and build-system maintenance, and mobile UI modules, he routinely tackles thorny integration and tooling problems that improve developer productivity. Notably, he pairs pragmatic bug fixes with larger architectural edits—such as React context and Flow integrations—demonstrating an ability to modernize legacy code while preserving stability.
15 years of coding experience
5 years of employment as a software developer
BS, Computer Science, Human Computer Interaction, BS, Computer Science, Human Computer Interaction at Carnegie Mellon University
Adds static typing to JavaScript to improve developer productivity and code quality.
Role in this project:
Back-end & Language Infrastructure Engineer
Contributions:3 releases, 13 reviews, 3560 commits in 8 years
Contributions summary:Marshall primarily contributed to the development and maintenance of the Flow type checker, as evidenced by modifications to the parser, AST mappers, and code action functionalities. Their work focused on improving the accuracy and reliability of the type system, including fixing parsing errors and handling inconsistencies in various code constructs. The user also worked on adding new features related to autocompletion, such as sorting and handling more complex code scenarios.
Contributions:7 releases, 1 review, 28 commits in 1 year 4 months
Contributions summary:Marshall primarily contributed to the Flow for VS Code extension, focusing on improving its functionality and reliability. Their work included fixing flow-bin verification on Windows, removing the legacy non-LSP implementation, removing a deprecated configuration option, and upgrading the bundled node version. They also upgraded the extension's build process by upgrading rollup, and they addressed a security concern related to logging by disabling a specific option.
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