How do you work with designers and product managers on mobile features?

Show that you engage before implementation, since mobile has constraints designers may not think about.

• Review designs early and raise platform realities. Material Design conventions, back navigation behaviour, system bars and gesture insets, keyboard behaviour, and how the layout survives a 320dp-wide screen or a 200% font scale.
• Ask about the states designs usually omit — empty, loading, error, offline, and very long content. On mobile, offline is not an edge case.
• Quantify cost rather than refusing. "That animation is possible but it needs a custom view and about three days; this alternative gets the same effect in half a day" is a conversation.
• Push back on anything that hurts accessibility — touch targets below 48dp, poor contrast, or text that does not scale.
• Get something running early. A rough build on a real device surfaces problems no mockup reveals, because a design that looks good on a laptop can feel wrong in the hand.

Note: Mentioning that you flag when a design fights platform conventions — for example an iOS-style pattern that confuses Android users — shows you advocate for the user rather than just implementing tickets.