1 answer published. Last candidate submission on Nov 29 2025, 3:46am PDT. Interview question asked to Machine Learning Engineers, Production Engineering Managers, ML Engineering Managers and other roles interviewing at MuleSoft, Electronic Arts, General Motors and other companies. Original question asked: Design a notification service.. Question last reported by a candidate interviewing at Hitachi for a Machine Learning Engineer interview on Sep 9 2026, 1:40am PDT.