I applied online. The process took 2 weeks.

The first round is just to see how your technical abilities are, and if you really fit well into the company. It's a really good opportunity to ask the interviewer about the tech stack Stripe uses. The interviewer was the engineering manager, and he was really lovely to chat to.

The next round is technical, where they ask you in-depth technical questions, and general algorithms, data structures, etc.

My programming stack was different to what they usually use, so they'd asked me: how would I fit in, and catch up? Especially since it was a senior position.