Jakarta, Indonesia has become the world's most populous city, overtaking Tokyo under new UN rules that include the wider metro area. The city faces big problems like extreme heat, floods during monsoon season, heavy pollution, and constant traffic jams. Jobs are hard to find too. Fitri Sartika Rama, a 22-year-old midwifery teacher, says, "It is a good place to live if you are young and focused on your job and making money." She adds, "Jakarta is OK for a short time, but I don’t want to live here in the long term." She sees Jakarta as "a young person’s city" where ambition pays off but life is tough every day.