How to concatenate two sequences with a separator?

Short answer: var seq1 = new[] { "Alice", "Bob" }; var seq2 = new[] { "Charlie", "David" }; var concatenated = se

Example code

var seq1 = new[] { "Alice", "Bob" };
var seq2 = new[] { "Charlie", "David" };
var concatenated = se

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.