San Diego-based productivity software developer ClickUp said this morning that it has raised a huge, $400M Series C funding round, which gives it a valuation of $4 billion. The Series C funding was co-led by co-led by Andreessen Horowitz and Tiger Global, with participation from Lightspeed Venture Partners and Meritech Capital Partners. ClickUp is led by Founder and CEO Zeb Evans. According to the company, it has tripled its revenue, and now counts such clients as McDonalds, Booking.com, Papa Johns, and Netflix as customers. The company has now raised $535M in total. According to ClickUp, the funding will go to expand its footprint and hire talent.