What does designing mobile first mean, and why is it useful?
What the interviewer wants to hear
- Start with the smallest screen and core content
- Forces prioritisation of what matters
- Consider touch targets, thumb reach and context
- Progressively enhance for larger screens
- Performance and network constraints
Model answer
Mobile first means I design for the smallest screen first and then expand to tablet and desktop. The small screen forces me to prioritise: there is room only for the core content and the main action, which usually makes the desktop design cleaner too. I also think about how people use phones: one hand, thumbs reaching the bottom of the screen more easily, large enough touch targets, interruptions and slower networks. So I keep pages light, put primary actions within reach and avoid hover-only interactions. Then, at larger breakpoints, I add layout columns, show more detail and use the extra space for things like side navigation. Many products get most of their traffic on mobile, so starting there aligns the design with how most users actually experience it.
Can you answer it under time pressure?
Take a timed easy round and get scored on every answer.
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