After signing the NDA, you will be contacted to arrange the interviews. Mostly basic questions to get to know you. Your skill and experience are taken for granted, based on getting to this point. A few aircraft specific questions, limitations and memory items.
Also some basic ATPL knowledge - try to review "how to ace the technical" as there will be questions covered by that book (meteorology and theory of flight).
Important: be confident, and make sure to discuss your expected salary even if not asked. If you mention a figure common to TREs in the region, you are under-selling yourself. Commuting is available if you press for it and negotiate well.
Ask for what you want, as a lot will be asked of you. Zero scope for errors once you are in and SRA will own you, be prepared. After arrival in Riyadh things go smoothly but slowly. Good luck.