The problem for a Engineering Manager
- Functional: browse a catalog, play a video with seek/resume across devices and bitrates, support profiles and watch history.
- Non-functional: low startup latency (<2s), minimal buffering/rebuffering, global availability, an enormous read-heavy workload.
- Scale: ~200M subscribers, ~100K titles, petabytes streamed per day, tens of millions of concurrent viewers at peak.
- Consistency: watch history/resume points can be eventually consistent; playback must never stall on a metadata outage.
Out of scope (covered in detail below)
Billing, recommendations ML training, the studio/production side, downloads/offline, live streaming, and DRM — deferred and discussed in the dedicated section.
As a Engineering Manager, the system design round will probe people, delivery, and technical credibility. Be prepared to go deep on the areas a Engineering Manager owns and to articulate trade-offs clearly.
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