TCS Angular + .NET Interview Questions for 6+ years

Shared question set for 6+ years of experience. Topics and wording follow the supplied notes; these are questions, not official company guidance.

1. Explain the complete flow of your application from Angular to ASP.NET Core API to Business Layer to Database.
2. How would you design a scalable ASP.NET Core Web API? You have Transient, Scoped and Singleton services. How do you decide which lifetime to use?
3. Explain how the ASP.NET Core middleware pipeline works. Why does middleware order matter?
4. How would you implement global exception handling and logging in a production API?
5. How would you secure an ASP.NET Core Web API using JWT?
6. What is the difference between IEnumerable<T> and IQueryable<T>? When would you use each?
7. What is the difference between FirstOrDefault() and SingleOrDefault()?
8. What is deferred execution in LINQ?
9. Your EF Core query is taking several seconds on a large table. How would you investigate and optimize it?
10. What is the N+1 query problem in EF Core? How would you avoid it?
11. When would you use Include() and when would you use projection?
12. What is change tracking in EF Core? When would you use AsNoTracking()?
13. Why would you use the Repository Pattern? Do you always need it with EF Core?
14. Explain the difference between clustered and non-clustered indexes. How can indexing improve or hurt performance?
15. What are CTEs and window functions? Where have you used them?
16. A SQL query works fine with 1,000 records but becomes very slow with millions of records. What would you check?
17. An API returns thousands of employee records. How would you display them efficiently in Angular?
18. Your Angular application is making the same API request multiple times. How would you avoid duplicate calls?
19. When would you use switchMap, concatMap and mergeMap?
20. How would you prevent memory leaks from Angular subscriptions?
21. Explain Default vs OnPush change detection. When would you use OnPush?
22. How would you implement authentication and role-based authorization across both Angular and ASP.NET Core?
23. The API works in Postman but fails from Angular. What would you check?
24. Your Angular UI is completed, but the backend API isn't ready yet. How would you continue development and test the UI?
25. How would you implement caching? What would you cache on the Angular side versus the API side?
26. Explain how your application goes from a code commit to Production. What happens in your CI/CD pipeline?

Browse Angular + .NET question sets