FrontendHaltTesting·Advanced·Conceptual·1 min read
What causes false positives in visual tests and how do you prevent them?
Short interview answer
Nondeterminism: animation mid-capture, web fonts not yet loaded, timestamps and random data, and rendering differences between operating systems or browser versions. Prevent by disabling animation, waiting for fonts, injecting fixed data, and capturing in one pinned environment.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.