Decagon system design interview

Round 4 of 6 · 3 questions reported

Length: 60 min
Format: Design discussion
They grade: Clarifying load and latency first, covering failure paths
Heads-up: Topics come from the product: customer-support agents, retrieval with vector search, routing across LLM providers, an AI gateway with auditing.

Questions Decagon asks in this round 3

Design the security architecture for an LLM chatbotAI systemA company runs a customer-facing chatbot built on a language model. Design its security: protecting the bot from abuse and prompt injection, limiting the data it can see and the…
Last asked Sep 2026
Design a customer-service AI agent with tools and guardrailsAI systemYou built a small conversational agent with two tools for the take-home. Now design the real thing: a platform that runs AI agents for many consumer brands, over chat and voice…
Last asked Mar 2026
Design an evaluation harness for a customer-support AI agentAI systemA company's AI agent answers its customers over chat and takes actions through tools (refunds, plan changes, escalations). Every prompt, model, tool or policy change can break it…