A week before her son died Park Mi-suk asked him to quit his job. For more than a year, the 27-year-old had been working overnight shifts at a warehouse for the country's largest online retailer, Coupang. In that time, Park says, her son lost 15kg and often complained of how tired he was. The following week, Park found him unconscious and hunched over in the bath. Jang died in 2020 but six years on, Park is still fighting to end what she believes is the reason for his death: night-time deliveries.