Not hard, but it needs proper preparation to get passed. API questions are interesting and it requires more time than they suggested as the api document are not always provide the info you need.

The HR screen was brief and fairly generic, no real questions were asked. The recruiter explained the process and mentioned they would follow up, but they didn't. I had to follow up myself after two weeks. I was then sent a written project described as taking 2-3 hours. This was significantly misleading, completing it properly required navigating Stripe's API documentation and running API calls from scratch, which assumes prior knowledge of their systems. For someone coming from outside the Stripe ecosystem, this took considerably longer. I submitted my answers and received a rejection email less than 24 hours later, with no feedback on the exercise or any explanation of where I fell short. Overall, the process lacked transparency and respect for candidates' time. The written project is a significant investment with no guarantee of meaningful feedback in return.