Establish systematic confidence in UI behavior through the right mix of visual regression, interaction testing, and accessibility assertions. Treat testing as a design input, not a post-ship safety net. The goal is not maximum coverage; it is catching the bugs that matter most without drowning the team in maintenance. Consult the accessibility testing reference when the testing strategy needs automated axe checks, screen reader validation, or keyboard traversal tests. Consult the component accessibility reference when testing custom components for focus management, ARIA correctness, and keybo…