Really a very good talk on the Expression tree. Your explanation was very simple and understanable. Please improve the audio quality. It is very very low.
Can someone explain, what's the point of building expressions from rules (around 44:00)? Why not just use standard methods like Where and Select? Especially since the rules are applied to an IEnumerable and not IQueryable. One thing I can think of is that the rules might not be known at compile time, but what are the other possible use cases?
There are plenty are application use-cases for storing user-defined ordered rule sets in a table, loading in memory, converting to a predicate and then applying to a set of entities