Barsha South / Arjan new-tower apartment — what should I snag and check before the developer's warranty runs out?

The warranty/defects-liability window is your leverage, so spend it on what's expensive to fix later, not the cosmetic bits. Prioritise: any sign of water ingress or failed waterproofing (balconies, wet walls, around windows), AC that doesn't cool or drains badly, MEP faults (sockets, tripping, low pressure), and door/window seals, THEN the cosmetic finish snags. The way to make them act rather than stall is documentation: a written, dated snag list with photos, submitted formally within the defects period, referencing the warranty, phone calls achieve nothing, a paper trail does. Get an independent snag done if you can, a professional list is harder to dismiss than a homeowner's. A proper apartment renovation in Dubai or snagging specialist can produce that documented list and even liaise on the fixes. Submit before the period lapses, once it's gone, these same defects become your bill. Keep copies of everything you send.