To be honest we don't have a methodology. It's largely just learning via making – listening to what people want, and fitting the things we want around it.

The current Notion is actually 2+ years in the making. Last year this time the beta version fall apart (poor focus and implementation). We moved to Kyoto for a bit and built the whole thing from scratch.

Re: Inkling & Habitat. I went to Inkling as my first job out of school. It taught me how to work with others, and bought me time to study the history of the domain – it's always good to make mistakes on other people's money ;-) (Inkling's founder is also Notion's first investor.)

Re: FS. It has been invaluable especially for customer support (no more sending screenshots back and forth). It's a very powerful tool, we need to be really careful not to abuse it and invade the privacy of our users.