"Hamish McKenzie, a former Lead Writer at Tesla, co-founded Substack, a platform that allows independent writers to publish subscription-based newsletters. With $82.4 million raised from Y Combinator, Substack has become a significant player in digital publishing, enabling writers to monetize their content directly."
https://www.everythingstartups.com/article/the-11-tech-mafias-ruling-silicon-valley
McKenzie is described on that site as part of the Tesla mafia. Hmmmmm ...