Ruthless and no sympathy for the developer. Starts off with HR call where the typical HR questions are asked. Very unfriendly I must say.

Then, they send you a coding challenge. You must design a REST API for transactions and statistics. The GET method should return a statistics object of all the transactions done in the last minute and it has to run in constant time. They also ask for a bunch of status codes returned by the controllers. Also, unit tests. There are a bunch of integration tests which your solution needs to be able to pass.

They ask you to have a solution within two days after sending out the challenge, but they take several weeks to review it. In my opinion, it is not a challenged that can be solved in a couple of hours after a working day...

It is also, in my opinion, rather idiotic judging someone's skills based on a coding challenge. They seem to eliminate people without even checking how the person thinks about software engineering but rather based on a set of requirements which might be even fulfilled but then subject to the whims of their development team, which are very unclear upfront. Like I mentioned, this is all very difficult to manage in 2 days. In any case, at least they provide more or less detailed feedback as to why they've rejected you.

The code challenge was already described.