Pros
I was not a database expert when I first came here. I had worked on compilers and debuggers, and had a lot of C++ experience, but I didn't have any database experience. I was given some very interesting problems, some of which required real mathematics to solve. I have learned a lot about databases and about SQL and the implementation of SQL databases. It's been a great place for me to increase my technical skills. The company is a late stage startup, or perhaps an early mid stage company. There are still vestiges of the startup days, which means there is some technical debt in the product. This is completely what one would expect of a product at this stage, and the amount of technical debt is trivial compared to other companies at which I have been. The management is very conservative financially, which I think is entirely appropriate.
Cons
VoltDB is an agile shop. I am not really a fan of agile development, but it's not a bar to my learning things here. It's probably a sign of my advanced age. If you don't like agile you won't like it here.