My impulse reaction to your sales pitch is "their product probably doesn't work very well and is way too expensive." I know that's unfair, but this entire idea of "our platform automates away the tedium of Spark clusters" just strikes me as a bag of magic beans.
What would help a lot with drawing cynical, bitter people like me: case studies on your website. I know that's a lot to ask for a young startup. But actual details about either money or developer time saved with Data Mechanics - specific pains your customers were having and how Data Mechanics addressed them, or specific analyses your customers were able to do now that they're spending less time managing Spark. Running a big Spark job in the cloud is a huge financial risk, and many Spark users are much more concerned about this than the headaches involved with management - and again, my last experience with Databricks resulted in more cost and more headaches. I do not think I am alone here.
I am wondering if you're considering selling your Spark telemetry/parameter tuning/etc software, or offering it as a service, etc. Speaking personally, I would be much more open to using Data Mechanics's tools on my own Spark cluster rather than outsource the actual management. At my organization, in addition to AWS, we also have a local Hadoop cluster with Spark installed; commercial software that gives better insight into its performance could be very useful.