Rich Harris, creator of Svelte, worked at the Guardian. Svelte has been adopted at NYT however [0].
You might be thinking of Mike Bostock, the creator of D3.js and ObservableHQ.com, who led data visualization work at NYT for several years [1]. I'm not sure if they have people of that magnitude working for them now.
Rich did work at the NYT. I thought there was some Mandela effect going on for a second, because you misled me into believing you had actually googled it by providing sources.
Yeah, my bad. I shouldn't have relied solely on the Wikipedia article and my (sketchy) memory. Rich Harris is still listed as a graphics editor on the investigative team at NYT: https://www.nytimes.com/by/rich-harris
Might want to update the Wiki article on Svelte, which strongly implies Rich worked at The Guardian, not NYT. The only source I could quickly find that seems to corroborate what you're saying is a LinkedIn page, but because of its bullshit paywall, there's context missing.
