What are common mistakes teams make with ASP.NET Core when using SOLID Design Principles?

Short answer: ASP.NET Core is cross-platform, uses Kestrel, middleware pipeline, and built-in DI. Requests flow: routing → middleware → endpoints → filters → action.

How to structure your answer (60–90 seconds)

1. Define ASP.NET Core in plain language for SOLID Design Principles.
2. Context — where it appears in a typical .NET project.
3. Example — one sentence from work, internship, or a practice app.
4. Trade-off — what you gain vs what you sacrifice.

Real-world example

A ShopNest checkout API registers authentication middleware before authorization, uses scoped DbContext, and returns ProblemDetails for errors.

Step-by-step talking points

1. Draw the request pipeline
2. Explain middleware order (auth before endpoints)
3. Mention DI lifetimes (scoped per request)
4. Give one production tuning tip (compression, caching)

Mistakes to avoid

• Blocking async calls in controllers
• Singleton service holding scoped DbContext
• Missing HTTPS redirection in production

Practice aloud. Pair this with the full SOLID Design Principles interview library and timed practice exams on Toolliyo.