Reading the article it mostly sounds like someone pretty new to an ecosystem leveling up to an ok level - so more like 0.1x developer (newb) to 1x developer than 1x to 100x.

There's a lot of value in skipping months of familiarizing oneself with a certain framework/language and immediately being productive but it doesn't read like the output of someone like Fabrice Bellard (a 100x in my book).