Pros
Circonus has a very strong culture of honesty and integrity that's reflected in every aspect of the organization. In the business itself, there is no distinction between customer and user, and the business model is transparent: So-called "dark patterns" of revenue maximization are non-existent. In the product, we built mathematically sound solutions to address customer needs, rather than (unfortunately more common in this space) naive implementations, that add a sales bullet point, but that would have resulted in misleading summary statistics. Data integrity was taken very seriously in my time there, as was operational security. We tried to solve important customer problems in the right way.
Cons
Some NIH syndrome in parts of the technical stack. The product UI never really gelled for me, which took something away from my pride in the product we built.