San Francisco-based Slack, provider of collaboration tools and services, announced it has raised $427 million in Series H funding at a post-money valuation of more than $7.1 billion. Lead investors in the Series H equity round are Dragoneer Investment Group and General Atlantic. They were joined by funds and accounts advised by T. Rowe Price Associates and funds advised by Wellington Management, and Baillie Gifford and Sands Capital, as well as existing investors. The company has now raised nearly $1.27 billion since it was founded in 2009.