In addition to Vlad's contribution, I can offer the following advice based on my experience with OW Dubai and London:
- Prepare for brainteasers - these seem less frequent recently, but are still common amongst interviewers
- Take the initiative and provide precise quantative answers - OW interviewers will frequently ask for precise results (e.g. to 3 decimal points), rather than for approximate figures
- Demonstrate the firm's value proposition to you - solid reasons why OW stands out to you will go a long way (e.g. positioning in Financial Services, flexible Global Staffing Model, growth rate)
Feel free to reach out offline if you have any specific questions on the firm or the geography you are applying to. Best of luck!