I applied online. The process took 3 months.
Challenging, but practical and with clear expectations. You won't need to do as much preparation for the technical rounds since they have far less focus on DSA and instead assess things like your fluency in your chosen programming language/environment, real-world practical skills (i.e. debugging, filesystem IO, working w/ structured data like JSON/CSV, calling REST APIs), working with ambiguity, collaboration, etc. Speed is extremely important as well.
I completed five rounds total including:
Multi-part questions to implement and iterate on a feature or task which processes some structured input in a non-trivial way, possibly calling out to APIs.
Identify and fix failing tests in a large open source repo.
The following metrics were computed from 368 interview experiences for the Stripe Software Engineer role.
Stripe's interview process for their Software Engineer roles is extremely selective, failing the vast majority of engineers.
Candidates reported having very good feelings for Stripe's Software Engineer interview process.