A distributed locking library built on top of Cloud Spanner. It uses Spanner's TrueTime and transactions support to achieve its locking mechanism. This library is also one of the main building blocks of hedge, another one of our production staples. For context, spindle has been in our production for quite some time and is used in several critical services. The biggest deployment size running spindle is about ~100+ pods with unpredictable scaling schedules. Between k8s scaling triggers and multiple service deployments in a day, spindle so far has held its own, running like clockwork. With that said though, spindle also works on single-pod deployments.