What actually makes a random forest work, beyond 'it averages a bunch of trees'?
Anyone can say 'ensemble of trees'. The real answer concerns decorrelating those trees and why that, not averaging alone, is what drops variance. Here is what makes the forest more than the sum of its trees.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
Anyone can say 'ensemble of trees'. The real answer concerns decorrelating those trees and why that, not averaging alone, is what drops variance. Here is what makes the forest more than the sum of its trees.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
