ASP.NET Developer Interview Questions Guide

Introduction

Hiring the right ASP.NET Developer is critical for IT teams building reliable web and API solutions. A well-structured interview process helps identify candidates who combine technical knowledge with practical experience.

This guide includes role-specific questions for basic, intermediate, and advanced levels plus five pre-screening one-way video interview prompts ideal for ScreeningHive. Use these questions to standardise screening, reduce time to hire, and compare candidates objectively.

ASP.NET Developer Interview Questions

Basic ASP.NET Developer Interview Questions

• What is ASP.NET and how does it fit within the .NET ecosystem?
• Explain the main differences between ASP.NET Web Forms and ASP.NET MVC.
• What are the primary benefits of ASP.NET Core compared to the .NET Framework?
• Describe the ASP.NET page or request lifecycle and name key events you work with.
• What is ViewState and when should you avoid using it?
• How does routing work in ASP.NET MVC and ASP.NET Core?
• Describe common techniques to manage session state in a web application.
• Explain the difference between authentication and authorization in ASP.NET.

Intermediate ASP.NET Developer Interview Questions

• You need to build a RESTful API for a new service. How would you structure controllers, DTOs, and model binding to keep the API maintainable?
• A web page is loading slowly under moderate traffic. What profiling steps and code changes would you apply to identify and fix the bottleneck?
• Describe how you would implement dependency injection in an ASP.NET Core project and why it is beneficial.
• Explain how you would use middleware in ASP.NET Core to add cross cutting concerns such as logging or error handling.
• How do you design and run database migrations with Entity Framework while minimising downtime?
• Provide an approach to handle concurrency when multiple users update the same resource concurrently.
• How would you implement pagination, filtering, and sorting in an API to support large datasets?
• Describe your approach to unit testing controllers and services in an ASP.NET application. Which frameworks and patterns do you use?
• How would you secure an API endpoint that must be accessible only by certain roles or clients?
• Explain strategies to deploy an ASP.NET application to IIS and to a containerised environment. What differences do you consider?

Advanced ASP.NET Developer Interview Questions

• Design a scalable architecture for a high-traffic ASP.NET Core application. Which components would you separate and why?
• How do you implement distributed caching and what factors influence cache invalidation strategies?
• Describe techniques for diagnosing and resolving memory leaks in a long-running ASP.NET process.
• Explain how you would migrate a legacy ASP.NET Framework monolith to ASP.NET Core with minimal disruption.
• Detail a secure authentication and authorization architecture using OAuth2 and OpenID Connect for web and API clients.
• How do you design APIs and services for fault tolerance and graceful degradation?
• Discuss performance tuning at the garbage collector and JIT compilation levels. What settings or patterns have you applied?
• Explain practices for observability in distributed ASP.NET applications, including logging, metrics, and tracing.
• Describe how you would lead a team through a major refactor or platform upgrade while maintaining delivery commitments.
• When would you recommend microservices for an ASP.NET-based system and how do you address data consistency and inter-service communication?

Pre-Screening Video Interview Questions for ASP.NET Developer

These five questions are suitable for one-way video interviews on ScreeningHive. They evaluate communication, practical experience, problem solving, and architectural judgment while providing recruiters with consistent candidate responses.

1. Describe a recent ASP.NET project you worked on and your specific contributions.

   This evaluates practical experience, role fit, and clarity in explaining responsibilities and outcomes.

2. Explain how you diagnosed and fixed a performance issue in an ASP.NET application.

   This assesses problem solving, technical depth, and familiarity with profiling and optimisation tools.

3. Walk through how you would secure an API endpoint that exposes sensitive data.

   This checks understanding of authentication, authorization, encryption, and security best practices.

4. Discuss a time you improved application reliability or reduced errors in production. What steps did you take?

This evaluates operational awareness, incident handling, and measures that improve stability.

1. Describe your approach to testing and deploying code safely. Include tools and processes you use.

This gauges knowledge of CI CD, automated testing, rollback strategies, and deployment hygiene.

Conclusion

These role-specific questions help hiring teams and candidates focus on the skills that matter for ASP.NET Developer roles in IT. Use the basic, intermediate, and advanced sets to match the seniority level you need.

ScreeningHive one-way video interviews provide faster screening and standardised evaluations so recruiters and hiring managers can compare candidates objectively and reduce time to hire.