SAN FRANCISCO — One by one, they left. Some quit. Others were fired. All were Black.The 15 people worked at Coinbase, the most valuable U.S. cryptocurrency start-up, where they represented roughly three-quarters of the Black employees at the 600-person company. Before leaving in late 2018 and early 2019, at least 11 of them informed the human resources department or their managers about what they said was racist or discriminatory treatment, five people with knowledge of the situation said.One of the employees was Alysa Butler, 25, who worked in recruiting. During her time at Coinbase, she said, she told her manager several times about …
