Ask HN: Successful Saas owners, how long did your first version take to build?

It's amazing to me how long it can take to get a saas app done. Even a seemingly simple looking one. Very interested to hear how long people here took to get their first iterations out the door! I'd also be interested in hearing about the stack you used. And if you had to make any significant changes to it over time, such as rewriting the entire codebase in a new language.