Technical screening questions
Ask for one example per question and listen for specifics.
- What is the difference between .NET Framework and modern .NET? A good answer: Cross-platform support, performance, side-by-side versioning and the migration path.
- How does dependency injection work in ASP.NET Core? A good answer: Service lifetimes: transient, scoped and singleton, and common mistakes.
- How do async and await work, and what is a common pitfall? A good answer: Avoiding blocking calls like .Result and understanding deadlocks.
- How do you handle database migrations safely? A good answer: EF migrations, review of generated scripts and rollback plans.
- How do you secure a Web API? A good answer: JWT or OAuth, authorization policies and input validation.
Quick screening questions
Use these when you have only a few minutes.
- Are you on .NET Framework or modern .NET, and have you migrated?
- How do you manage dependency injection and configuration in ASP.NET Core?
- Describe how you secured a Web API.
What separates the levels
Match the level to the requirement before you submit.
- Junior: implements endpoints and fixes bugs.
- Mid: owns features, writes tests and tunes queries.
- Senior: leads migrations, designs services and reviews code.
Red flags
Any of these is a reason to probe further.
- Only worked with legacy Web Forms.
- Cannot explain service lifetimes.
- No experience with SQL beyond basic queries.
Tools you should hear mentioned
A .NET developer with real experience usually names several of these without prompting.
- ASP.NET Core
- Entity Framework Core
- SQL Server
- xUnit or NUnit
- Azure DevOps
- Visual Studio
Run the call well
Ask for the last project first, then dig into the second or third question. Take notes on versions, team size and outcomes, and record them with the submission so the vendor’s later technical interview does not surprise you.
Frequently asked questions
How long should a .NET developer screening call take?
Fifteen to twenty minutes is enough to cover the project, three technical questions and availability, rate and work authorization.
Do recruiters need to know the technology?
Working vocabulary is enough. Use the sourcing guide for the role and listen for specifics instead of judging technical depth yourself.