There has been lots of recent activity amongst 'AI platform' companies planning IPOs: see Databricks, Data Robot, Domino, Palantir, and now C3.ai.
C3.ai provides AI services to large companies and has worked with Shell, AstraZeneca, conEdison, Koch Industries, Raytheon and also the US Airforce. The company is focused on a small number of large clients and seems to do a bit of everything for them. Its main customer is oil and gas service company Baker Hughes. It's not clear from this document what the company competitive advantage is.
"As often for AI companies, there is some level of questioning about what part of their activity is actually AI, vs more traditional software, and C3 is no exception. See for example this piece in ZDNet: Dissecting C3.ai’s secret sauce: less about AI, more about fixing Hadoop"
A problem for this type of company is that 'AI' is such a loosely defined term: any attempt to build a platform for it leads to a lack of focus. Companies are often trading more on hype that actual outcomes. I'm sure there will be eventual big winners here, but I'm not sure they exist just yet.