Your question is Extensible Schema Design for Ramp. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
As products like Ramp cards, reimbursements, bill pay, and approvals expand, schema decisions made early can either speed up iteration or create long-term migration pain. Interviewers ask this to see whether you can balance flexibility with strong relational design.
Explain how you would design a highly extensible PostgreSQL schema for a fast-growing product. You should discuss how you would model shared entities versus product-specific attributes, how you would handle new fields and workflow states over time, and how you would preserve data integrity and query performance as the schema evolves.
Keep your answer practical and SQL-focused. The interviewer is not looking for distributed systems design; they want to hear how you think about normalized core tables, optional extension patterns such as JSONB or subtype tables, constraints, indexing, and migration strategy in a product like Ramp where reporting and operational correctness both matter.