Interview prompt
Problem context
A company needs a global streaming platform. A managed vendor meets current needs but costs more at projected scale and uses proprietary semantics. Building on open-source software offers control but requires a new on-call team. Leadership wants an architecture recommendation, not a feature checklist.
Skills being evaluated
build-versus-buy analysisvendor riskoperating modeloption value
The full reasoning guide is part of Pro
The scenario and evaluation focus above remain public. Pro unlocks the structured answer, trade-off analysis, follow-up probes, common weak answers, rubric, related reasoning, and any architecture diagram.
Sign in to continueWhat the full guide covers
Clarify the decision
Establish scale assumptions
Functional and non-functional requirements
High-level architecture
Data model and flow
Consistency and transaction boundaries
Failure modes and recovery
Security and privacy
Observability and SLOs
Capacity and cost
Alternatives and trade-offs
Evolution and migration
What Staff and Principal candidates should emphasize