Workplace collaboration platform Slack has closed its long-rumored new round of funding at $250 million, led by SoftBank’s Vision Fund, as it seeks to beat back a growing list of competitors with deep pockets.

According to Bloomberg, Slack said it is still sitting on most of the $591 million it had previously raised. The latest round will give the company “operational flexibility.”

San Francisco-based Slack has been one of Silicon Valley’s hottest startups in recent years. But that success has attracted numerous competitors, including Microsoft, which launched Teams earlier this year; Atlassian, with its HipChat service workplace collaboration; Google, which launched Hangouts Chat this year; and Facebook, which is still pushing its Workplace service.

So $250 million only sounds like a lot of money until you look at those competitors’ balance sheets.

Still, according to Bloomberg, Slack has passed 9 million weekly active users and 6 million daily active users. In addition, it has 2 million paid customers and 50,000 paid teams, and its revenues are $200 million. As the company continues its international expansion, it’s also counting on a growing number of developers who write for its platform to help it maintain its edge.