Justin Grant
Product Advisor at AON3D
Berkeley, California, United States
Summary
🤩
Rockstar🎓
Top SchoolJustin Grant is a product advisor and veteran product leader based in Berkeley with 10+ years steering B2B UX, Vertical SaaS, and API-led products at Bay Area startups and established tech firms. He blends hands-on engineering experience—from early full‑stack work and patents at Microsoft to contributions as a QA and back-end contributor on high-profile ECMA TC39 projects like Temporal—with practical product strategy and GTM execution. Justin has led product and growth teams to measurable results (e.g., 3.6x paid signup improvement at UpCodes) and now advises hardware-software companies like AON3D on SaaS roadmaps and UX. As an invited expert on the JavaScript standards body he co-led the design and polyfill work for Temporal, demonstrating rare cross-disciplinary fluency between standards-level engineering and user-facing product design.
10 years of coding experience
26 years of employment as a software developer
B.A., B.A. at University of California, Berkeley
Github Skills (13)
debug10
typescript10
javascript10
typescripts10
api10
temporal10
ecmascript10
typescript-types10
test-automation10
testing10
iso9
algorithm7
algorithms7
Programming languages (17)
Github contributions (5)
tc39/proposal-temporal
May 2020 - Jan 2023
Provides standard objects and functions for working with dates and times.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:768 reviews, 208 commits, 240 PRs in 2 years 8 months
Contributions summary:Justin primarily contributed to the development of the Temporal proposal by fixing bugs and improving the codebase. They addressed an infinite loop issue in Chrome's `GetFormatterParts` function, introduced and refined TypeScript types for the polyfill, and removed the `balance` disambiguation option from non-Duration types. The user also made adjustments to calendar-related functionality and other minor updates to the polyfill.
datetimedates-and-timesdate-parsertimeagotimes
tc39/test262
Oct 2021 - Jan 2023
Official ECMAScript Conformance Test Suite
Role in this project:QA Engineer / Test Automation Engineer
QA Engineer / Test Automation EngineerContributions:32 reviews, 8 commits, 17 PRs in 1 year 2 months
Contributions summary:Justin primarily contributed to the test suite for the ECMAScript Conformance Test Suite. Their commits include reverting changes to tests, verifying the non-writeable nature of prototype properties, and fixing test failures under specific Node.js versions. These changes demonstrate a focus on maintaining the accuracy and reliability of the test suite, specifically related to Temporal objects. Furthermore, the user ensures the tests' compatibility with various environments by addressing compatibility issues across Node.js versions, which involves modifying existing test cases.
javascriptconformancetc39typescripttests
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