It's essential to demonstrate that you can really go deep... there are plenty of followup questions and (sometimes tangential) angles to explore. There's a lot of Applications Support Engineer experts who've worked at Raisin, who provide this sort of practice through mock interviews. There's a whole list of them curated on Prepfully. prepfully.com/practice-interviews
Thank you for your feedback. It is unfortunate that you were not successful in your application and your questions could not be answered at the early stages of our recruitment process. We will take your comments on board and improve our process. Our salary ranges are competitive for the local market, contrary to your assumptions.