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Design a Single-Domain Chatbot

Last updated: Apr 6, 2026

Quick Overview

This question evaluates a candidate's ability to design production-grade conversational AI systems, testing competencies in retrieval-augmented generation, document ingestion and indexing, multi-turn session management, prompt construction, model serving, grounding and citation, safety, access control, monitoring, and operational trade-offs.

  • medium
  • Decagon
  • ML System Design
  • Software Engineer

Design a Single-Domain Chatbot

Company: Decagon

Role: Software Engineer

Category: ML System Design

Difficulty: medium

Interview Round: Onsite

Design a chatbot system for a **single enterprise customer** and a **single business domain**. For example, the chatbot may answer support questions for one product line or one internal knowledge domain. The system should: - support multi-turn conversations, - answer questions using the customer's approved documents and FAQs, - provide grounded answers with citations or source references, - avoid hallucinating unsupported information, - allow administrators to update the knowledge base, - support fallback to a human agent when confidence is low, - meet reasonable latency and cost targets. Discuss the end-to-end design, including: - user-facing APIs and session management, - document ingestion and indexing, - retrieval and ranking, - prompt construction and model serving, - safety and access control, - monitoring and evaluation, - scaling and reliability trade-offs.

Quick Answer: This question evaluates a candidate's ability to design production-grade conversational AI systems, testing competencies in retrieval-augmented generation, document ingestion and indexing, multi-turn session management, prompt construction, model serving, grounding and citation, safety, access control, monitoring, and operational trade-offs.

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  • Design a Real-Time AI Voice System - Decagon (medium)
Decagon logo
Decagon
Mar 9, 2026, 12:00 AM
Software Engineer
Onsite
ML System Design
10
0

Design a chatbot system for a single enterprise customer and a single business domain. For example, the chatbot may answer support questions for one product line or one internal knowledge domain.

The system should:

  • support multi-turn conversations,
  • answer questions using the customer's approved documents and FAQs,
  • provide grounded answers with citations or source references,
  • avoid hallucinating unsupported information,
  • allow administrators to update the knowledge base,
  • support fallback to a human agent when confidence is low,
  • meet reasonable latency and cost targets.

Discuss the end-to-end design, including:

  • user-facing APIs and session management,
  • document ingestion and indexing,
  • retrieval and ranking,
  • prompt construction and model serving,
  • safety and access control,
  • monitoring and evaluation,
  • scaling and reliability trade-offs.

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