Design a Food-Ordering Chatbot and Evaluate Its Post-Training

Asked at DoorDash · System Design for ML · Difficulty: Hard · Last asked Nov 7, 2026

Design a customer-facing chatbot that lets people order food from restaurants in a delivery marketplace, and plan how the language model behind it is post-trained and evaluated before launch. A customer types requests in plain language, the chatbot helps them choose items, handles customisation, and places the order. Some customers state dietary restrictions or allergies, and some menu items have very large option spaces, such as a build-your-own hot pot where the customer picks a broth, a spice level and many ingredients.

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