We are clearly one of the largest CA’s in the world, however the largest depends highly on one how you measure. In any case we represent, again depending on how you measure, between 1/4th and 1/3rd of the worlds total SSL certs. And I am told by a number of people who have worked on our system and others, as well as by our auditors, that we are one of the finest CA’s in the world.
While I have little to do with the application development, and the current architecture was mostly inherited, I do manage the databases for this. At one time we also boasted the worlds most efficient OSCP responded written by my former boss Chris G. I can not say enough good things about him, and the entire team I work with. They are all amazing people! The environment went stagnant for a bit but I am proud of where we are going with PKI; as these handful of instances our now my secure baby 🙂