A Brief Introduction To Our Dialer System We handle a fairly large amount of calls at Close, helping our customers connect with their customers ~9 million times a month. The core service that we’ve built to manage the lifecycle of each call is called the Dialer. We’ve designed it pretty well, so for quite a few years – and a couple bumps in the order of magnitude of call volume – it carried on with only minuscule tweaks. And then, one fateful day, it started becoming much slower, its database’s ...