Sebastiaan Lokhorst
Software-ingenieur at HTR Rotterdam B.V.
Randstad, Netherlands
Summary
🤩
Rockstar🎓
Top SchoolSebastiaan Lokhorst is a software engineer based in the Randstad with 11 years of hands-on experience building web applications and developer-facing features. With a background in Applied Physics (MSc) from TU Delft, he blends analytical rigor with practical full‑stack engineering, currently contributing at HTR Rotterdam and freelancing through Phixi. He has made notable open-source contributions to high‑visibility projects like the MDN Service Worker cookbook—improving push notification reliability and integrating VAPID—and to the ECMAScript compat-table, helping clarify browser support for modern JS features such as globalThis and Object.fromEntries. Comfortable across front-end and service-worker ecosystems, he focuses on robustness, progressive web capabilities, and cross-browser compatibility. Colleagues would describe him as a pragmatic problem-solver who brings academic discipline to production code and cares about improving developer and user experience.
11 years of coding experience
TU Delft
Github Skills (15)
html10
service-worker10
compatibility10
compatible10
javascript10
backward-compatibility10
apple-push-notifications10
push-notifications10
ecmascript10
browser-support10
testing10
front-end-development9
git-repository8
git8
github8
Programming languages (22)
Github contributions (5)
mdn/serviceworker-cookbook
Jan 2018 - Apr 2018
It's online. It's offline. It's a Service Worker!
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:11 commits, 8 PRs, 2 pushes in 2 months
Contributions summary:Sebastiaan primarily focused on enhancing the push notification functionality within the service worker cookbook. They updated multiple HTML files to use the `.webmanifest` extension for manifest files. Additionally, they integrated VAPID for secure push notification delivery across various push recipe implementations. Finally, they refactored and optimized existing push-related code and fixed bugs for better user experience.
service-worker
compat-table/compat-table
Sep 2017 - Dec 2018
ECMAScript compatibility tables
Role in this project:Full-stack Developer
Full-stack DeveloperContributions:5 commits, 6 PRs, 2 comments in 1 year 3 months
Contributions summary:Sebastiaan primarily contributed to the compatibility tables for ECMAScript, focusing on the `Array.prototype.values` and `globalThis` features across various browsers and JavaScript environments. Their work involved updating the compatibility data, including status changes, and integrating the results for various browser releases. The user also added information for the `Object.fromEntries` method. This includes adding and updating the status of the feature in the compatibility tables.
ecmascript
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