How do you design a low-cognitive-load wizard and implement it technically?

WHAT IT TESTS: your ability to pair progressive disclosure with robust frontend architecture. A strong answer covers four elements: first, showing only relevant fields per step with clear progress indicators; second, step-level validation blocking advancement on errors; third, a state machine or URL-synced state for branching and back buttons; fourth, isolated step components receiving draft data and emitting validated updates. RED FLAG: describing one giant form using only local useState with no step boundaries or partial-save handling.