He posted here a while back, paraphrased "My revenue model is my bank account has 10 digits". He's wealthy and likes to code and is giving back to the community

He's a billionaire, has sponsors and has a startup.

He has billionaire investors. Probably the only grey note about his ventures here.

"Mitchell Hashimoto is a software developer and entrepreneur best known as the co-founder of HashiCorp, which was acquired by IBM for $6.4 billion in 2025."

Many common ways for the financing of an free and open source project to be sustainable (The main keyword) in the mid to long term:

1) A non-profit company that has full-time employees but supported via sponsorships: (gnu project, mastodon, omarchy, zig)

2) Multiple for-profit companies that each have full-time employees contributing to an open source project that they all use: (ocaml, linux, rust)

3) An ultra high net worth individual that has full-time contributors to open source and supported via a non-profit (signal, ghostty)

4) A for-profit company that has dedicated full-time employees that have full support and own the direction of the open source project (go, swift, java)

5) VC funded open source projects (Herdr, Bun, Deno, Burno, Atuin)

All other options such as low donations like "buy me a coffee", ko-fi, are completely unsustainable, now that AI agents exist.

https://en.wikipedia.org/wiki/HashiCorp