4 stages.
Overall, they value teamwork, communication and excellent iOS development and engineering skills.
Once you pass the first stage, you have the option to do the remaining stages in one day or split over two days. I recommend doing it in two days, that is, 1 full day for the second stage and another day for the culture and product interviews.
1. Introductory interview + mini technical challenge.
This is a straightforward interview talking about how it is working at Curve and the current tech stack they currently use.
Brief introduction on what you do and how you've contributed to other businesses or your other past positions.
Small technical exercise which should be easily solved within 15min.
2. In-depth code review style interview.
This exercise includes a buggy project which needs some refactoring and possible changes that you might want to introduce.
They assess you on what you would prioritise first and how you approach solving the problems that the project has.
It's an interactive code review where other interviewers will be assessing your skills. I would strongly advise to prepare some notes on how to tackle each issue or improvement that you want to address and be methodical about it.
The next two parts are more focused on communication and project/product management. They are in the form of a discussion/debate to check if you would be a good fit for the company.
3. Culture interview
This part of the interview process is more relaxed. Curve will ask you questions about their leadership principles (which they will send over after the first phase) and overall project management communication.
4. Product interview
Here you will be asked about what you know about Curve and I strongly advise you to do your own research about the company as this will be a massive bonus for them to take an interest in you.
Overall, being proactive and showing genuine interest in the company and the product(s), as well acing the technical questions should put you on the right path.