Easy, very easy. It consists in a phone interview with HR, followed by a simple technical test in C# and the final interview with HR, tech lead, developer and product manager the same day.
The test is quite easy, just a unit test showing TDD skills, and the objective is to add items to a shopping cart. Just a few lines of code, the easiest interview ever, but I failed! The reason... I exposed the cart items in a collection and they told me: "Why did you do it? We didn't ask you to do it", so I failed because I contributed somehow to make it look like a real online shopping cart, it seems to me not the real reason to fail an interview, maybe something related to my background or something else they didn't want to share. About me, I have a very strong resume, worked for big companies out there known worldwide and my contributions have been at architectural level. These companies build their products with people feedback and ideas, where everyone learns, contributes and succeeds. So I felt I cannot work for a company where I am not able to contribute, propose ideas, or positively disagree.
At business level, not very clear what is the product roadmap, I asked "What is the future of the product in a few years?"... the answer: "We don't know yet, we just want to keep our existing clients happy", at least the list of features advertised in the website don't match any of the goals of the company in the near future. Or maybe for confidentiality they didn't disclose such information, I think it was easier to tell me than look weak. Either way not good.
My recommendation for them is to listen to people when they bring some ideas, and please don't be disrespectful, "We didn't ask you to do this" and laugh is not a very motivating experience; remember the interview is a two way street for the interviewee as well. And for HR, please be more professional, if someone fails an interview, at least one email to tell the outcome is expected. I had to email and call for 5 days until he answered his phone, not good, really not good.
For new applicants, the bright side: Its a good company if you are looking for a relaxed environment, casual dress code, ping pong table for your breaks, and a great office location. If you are new in finance, this is a very good company to start. However, if you are experienced in finance, try to get all the information of the product roadmap and where will you be in 3 years, you will see then if this is a big step backward in your career, or maybe not, but use the interview to find this out, very important.