Process is fine, standard I would say. Maybe longer than expected, between interview there is lot of time with uncertainty if you are still in our not. The process consist of 4 stages: 1st with HR, 2nd technical challenge and a defense, 3rd with engineers and 4rd with product. All doable, the technical challente focused on web application with high concurrency access requirements.

An initial contact with the HR. They ask for an assessment that, according to them, takes 8 to 12 hours of coding. To do a good test you need a lot more than 12 hours unless you want to deliver a real shit. They never take into consideration the time you spent to think on a solution before counting these 12 hours, and of course, any quick implementation of a Digital Wallet use cases will not be fast. Be aware that you're not getting paid for all these hours of coding, as it happens in some companies. They ask you to collect the requirements with them by email. The thing is not about making a hard assessment, but the amount of time that they ask you to spend with their process. After the coding assessment, you have a technical interview of an hour more or less. And after this, you have 2 interviews to evaluate cultural and product fit. I'm pretty sure that there are better ways to evaluate the candidates on the subjects that they care about. An interview with direct questions could remove the need for 12 hours of coding to have a chance or to have nothing (because they'll not hire everyone). I'd rather prefer a living code of 1 hour and a half than coding for 12 hours or more for an interview. They also can move you til the last interview only to say you don't have product fit, what they could do at the beginning, but they are confident to have a wonderful interview process. If you value your time or don't have time for all of this: run away!