Agent System Design
Explore a complete, worked system design for a telecom customer service agent, from data and tools to security, evaluation, and cost. Learn to handle common interviewer follow-up questions and distinguish strong answers from weak ones.
With the scope agreed, the Veltra engagement moves from what to build to how to build it. The first release covers billing explanations and outage status in chat and the mobile app, ticket creation and handoff to human agents, and agent assist for human billing agents, for one country and one language. The design has to work with an on-premises billing API, a five-minute outage feed, EU data residency requirements, and a CISO who will not approve automated financial actions.
This lesson presents a worked design for that release, structured the way a strong candidate would present it in a 60-minute system design round. It then covers follow-up questions an interviewer is likely to ask, with examples of weak and strong answers to each.
Scope and success
A strong design opens by restating the scope and success criteria in a few sentences, so the interviewer and candidate agree on the target before any components appear.
The system resolves billing and outage questions for authenticated customers in chat and the mobile app, creates tickets when needed, and hands off to a human agent with a summary when it cannot help. Success means a higher share of billing chats resolved without a human, lower handling time on assisted contacts, customer satisfaction at or above the current baseline, and accuracy at or above an agreed threshold on a golden set of real billing and outage conversations.