FrontendHaltPerformance·Intermediate·Conceptual·1 min read
How do lab and field data differ?
Short interview answer
Lab data is repeatable and diagnostic under controlled conditions. Field data records real users, devices, networks, caches, and interactions. Use field data to understand outcomes and lab traces to reproduce and fix causes.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.