Jeffrey Posnick
Senior Engineer at Bloomberg
New York, New York, United States
Summary
🤩
Rockstar🎓
Top SchoolJeffrey Posnick is a senior engineer with 14+ years building developer-focused web platforms and tooling, currently shaping frontend systems at Bloomberg after leadership work on Two Sigma’s Frontend Platform. He spent 15 years at Google Developer Relations as a Staff Engineer and tech lead of Workbox, the TypeScript-powered service worker libraries used by high-profile PWAs such as TikTok, Hulu, Airbnb, VS Code Web, and Photoshop on the web. Jeffrey combines open-source design and technical writing—contributing code, docs, and webpack/service-worker integrations across projects like create-react-app, sw-precache, and web.dev—to make offline and caching behaviors easier for other engineers. His background spans full-stack and automation work from Chrome and Polymer tooling to YouTube and AdWords API samples, reflecting a pragmatic focus on developer experience and reliable runtime behavior. Remarkably, his contributions often bridge user-facing UX and build-time infrastructure, improving both how apps behave in the browser and how teams ship them. He holds a BA in Economic Philosophy and Computer Science from Columbia and brings cross-industry systems experience from Morgan Stanley through elite tech firms.
14 years of coding experience
18 years of employment as a software developer
Bachelor of Arts - BA, Economic Philosophy and Computer Science, Bachelor of Arts - BA, Economic Philosophy and Computer Science at Columbia University in the City of New York
Stackoverflow
54,738reputation
3.0mreached
1,143answers
5questions
websocket
top-5%
fetch-api
top-1%
caching
top-1%
google-api
top-5%
es6-promise
top-5%
jquery
top-5%
Github Skills (71)
apim10
dashboard10
caching-strategies10
youtube-api10
testing10
automation10
pwapp10
web-development10
html-webpack-plugin10
fetch-api10
javascript10
polymer10
gulp10
youtube10
service-worker10
Programming languages (18)
Github contributions (5)
GoogleChromeLabs/sw-toolbox
May 2015 - Apr 2019
[Deprecated] A collection of service worker tools for offlining runtime requests
Role in this project:
Back-end Developer
Back-end DeveloperContributions:5 releases, 106 commits, 73 PRs in 3 years 11 months
Contributions summary:Jeffrey primarily focused on modifying the `sw-toolbox.js` and `lib/router.js` files. These changes involved refactoring code, implementing new strategies like network timeout and cache expiration, and optimizing the service worker's caching behavior. The user also added options and adjusted caching logic to improve efficiency.
service-workerjavascriptservice-workersprogressive-web-appcaching
GoogleChromeLabs/preload-webpack-plugin
Dec 2017 - Jan 2021
Please use https://github.com/vuejs/preload-webpack-plugin instead.
Role in this project:Front-end Developer
Front-end DeveloperContributions:9 releases, 76 commits, 21 PRs in 3 years 1 month
Contributions summary:Jeffrey primarily contributed to the `googlechromelabs/preload-webpack-plugin` repository by modifying and enhancing the plugin's functionality, particularly related to how it handles preloading and prefetching resources within a webpack build. The user fixed issues related to the plugin's logic and recursion, and refactored code to align with changes in build tools. A significant focus was on refactoring and improving tests to ensure the plugin correctly handles various scenarios related to preloading and prefetching.
preloadvuewebpack-pluginpreload-pluginperformance
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