The last time I was responsible for interviewing, the project I was working on dealt with a lot of data transformation - get data from various APIs and databases, transform it and store it somewhere else. This is all .Net and we were storing data in Mongo. So we were always working with lists of strongly typed objects.
One simple problem was given a list of users objects, create a list of the target object and generate a userid from the first initial, first four of the last name.
Then we had an algorithm for how to handle ID clashes. We had failing unit tests for all of the corner cases.
We were hiring contractors and paying them well so we made one of the requirements that you had to know LINQ and EF. Even though we weren’t using EF that often, Linq is Linq and linq queries work the same with in memory lists, EF, and the C# Mongo driver.
It was a requirement that they used Linq instead of foreach loops since Linq gets translated to Sql and MongoQuery instead of doing the processing in memory.
