AI & Technical question

Design a VoIP service.

Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.

What this question tests

Technical product thinking: understanding the core components of a real-time voice communication system and their trade-offs.

Clarify scope: a consumer or business VoIP service for voice calls over the internet, similar to Twilio's own offering.
Identify core requirements: low latency, call reliability, and clear audio quality across varying network conditions.
Describe the architecture: call setup and signaling (e.g. SIP), audio codec choice, and media routing between callers.
Address reliability, such as handling packet loss with jitter buffers and fallback to lower-bandwidth codecs.
Discuss trade-offs, like audio quality versus bandwidth usage, and centralized versus peer-to-peer media routing.

Names concrete components: signaling protocol, codec selection, and media servers, not just 'make calls work.'
Addresses real degraded-network handling, like adaptive bitrate or jitter buffering to prevent choppy audio.
Discusses a genuine trade-off, like peer-to-peer routing reducing server cost but complicating NAT traversal.
Ties the design back to a product goal, like minimizing dropped or garbled calls for business customers.

Giving a purely abstract answer with no mention of signaling, codecs, or media routing.
Ignoring degraded network conditions like packet loss or jitter entirely.
Not discussing any real trade-off or cost consideration.

Chapters of the AI PM course that teach what this question tests.