I started with adaptive bitrate streaming and the interviewer seemed fine with that, but then I got a bit lost when they pushed on the metrics side.
Start by clarifying the streaming context (live vs. VOD, scale, device mix) and then structure your answer around the video pipeline: encoding, packaging, delivery, and playback. For each stage, propose concrete optimizations and tie them to measurable metrics like bitrate, rebuffering ratio, and QoE scores, emphasizing trade-offs between bandwidth savings and user experience.
Pro tip: Google values data-driven decisions, so quantify the impact of each optimization (e.g., 'switching to AV1 can reduce bitrate by 30% at equivalent quality') and mention how you'd A/B test changes to validate improvements without degrading QoE.
Ask about the type of streaming (live/VOD), scale, device diversity, and business goals to tailor your answer. This shows you avoid one-size-fits-all solutions.
Discuss codecs (AV1, HEVC, VP9), per-title encoding, and adaptive bitrate ladders to reduce bits while maintaining quality. Mention packaging optimizations like chunked CMAF and byte-range requests.
Leverage CDNs, edge caching, and P2P or multicast where appropriate. Consider protocol optimizations (HTTP/3, QUIC) and smart routing to minimize redundant data transfer.
Implement ABR algorithms that consider network conditions and device capabilities, and use techniques like buffer management and pre-fetching to avoid rebuffering while reducing unnecessary downloads.
List technical metrics (bitrate, bandwidth per session, CDN offload, rebuffering ratio, startup time) and user-centric metrics (QoE, engagement, churn). Explain how you'd monitor and A/B test them.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.