One of the main questions I ask in interviews is basically "we have a data pipeline with goal X and constraints A, B, and C. How would you design it?" Depending

One of the main questions I ask in interviews is basically "we have a data pipeline with goal X and constraints A, B, and C. How would you design it?" Depending on how they do, we'll discuss various tradeoffs, other possible goals/constraints, and so on. This is based on a real system I designed and have been maintaining for ~5 years, and is also very similar to other systems I've run at previous jobs. About half the candidates complain that it's not a realistic question.