

You will often need to choose between relational and non-relational storage when designing analytics, operational, or client-facing systems. In a Deloitte engineering interview, the interviewer wants to see whether you can compare the trade-offs clearly rather than just listing buzzwords.
Explain the key differences between SQL and NoSQL databases. You should compare their data models, schema design, transaction and consistency behavior, scaling patterns, and typical use cases. Also explain when you would prefer one over the other in an enterprise setting, such as a Deloitte-built data platform or client application.
Keep your answer practical and balanced. The interviewer expects you to cover structure, flexibility, ACID behavior, normalization versus denormalization, and horizontal scaling, while noting that the choice depends on workload and system requirements rather than one model being universally better.