Find employees in both List A and List B?

Short answer: var listA = employees.Take(3); var listB = employees.Skip(2); var common = listA.Select(e => e.Id) .Intersect(listB.Select(e => e.Id));

Example code

var listA = employees.Take(3);
var listB = employees.Skip(2);
var common = listA.Select(e => e.Id)
.Intersect(listB.Select(e => e.Id));

Real-world example (ShopNest)

ShopNest uses LINQ to query orders: filter by date, project to a summary DTO, and order by total—readable C# that becomes SQL under EF Core.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.