Explain the different isolation levels in ADO.NET transactions.
Answer: Isolation levels define the level of visibility one transaction has into the changes made by other concurrent transactions. The four isolation levels in ADO.NET are:
What interviewers expect
- A clear definition tied to ADO.NET in ADO.NET projects
- Trade-offs (performance, maintainability, security, cost)
- When you would and would not use it in production
Real-world example
In a production ADO.NET application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.
How to explain in the interview
- Define the concept in one or two sentences.
- Context — where it fits in ADO.NET architecture.
- Example — a specific project, bug, or performance win.
- Trade-off — what you gain vs what you sacrifice.
Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.