Doing well on the Jepsen tests is a very good sign. But it isn't anywhere near enough. Other things to consider: - The product has bugs not addressed by Jepsen

Doing well on the Jepsen tests is a very good sign. But it isn't anywhere near enough. Other things to consider: - The product has bugs not addressed by Jepsen. - Performance is inadequate. - The optimizer is immature, and you find yourself struggling to understand and work around its limitations. - Replication is missing or doesn't work well enough. - There is absolutely no substitute for N years of real-world experience, no matter how rigorous the company's testing. - Impossibility of finding people already familiar with the product, because they are all employed by the vendor. - Even aside from product issues, is the company profitable? If not, how long is it going to be in existence?