With a small amount of prompting I rewrote all the methods to more efficient versions. Again, top-tier pure FP programmers don't think in terms of optimization as the #1 prerogative. Code quality and maintainability generally take precedence. Even so, I wasn't asked to optimize MY code, but somebody else's. All of this I'd have no objection to if the information Trumid gave me about the interview was accurate, but it wasn't. There is absolutely no excuse for this. This is important: No software firm has any excuse for giving candidates objectively inaccurate information about an interview. Especially not in this market for Scala engineers. This is just a waste of everyone's time.