By 2012, when we published the Spanner paper, we had just completed the migration of AdWords frontend traffic to the new Spanner backend, and we knew we had the seed of something really interesting. Since then, we have been rapidly improving Spanner in every dimension. Google, like most businesses, needs databases that are fully managed, easy to deploy, highly available, and robust in the face of any workload. Google services set a high bar: Spanner stores a copy of the Internet (actually several, at different stages of the indexing pipeline) and is the bedrock of availability and durability for billions of users that depend on Google in their daily lives.Then, in 2017, Google Cloud launched Cloud Spanner, a fully managed database service that brought the unique capabilities of Spanner to every organization, allowing them to deliver always-on experiences at any scale from thousands to millions of active users across the world without sacrificing consistency.That took us down another road: innovating to make it easy for all enterprises to build data-driven applications using Cloud Spanner. This meant adding enterprise features such as CMEK and access approval, fine-grained access control, backup and restore, and point-in-time recovery (PITR). We also added VPC Service Controls support and compliance certifications and necessary approvals so that Spanner can be used for workloads requiring ISO 27001, 27017, 27018, PCI DSS, SOC1|2|3, HIPAA and FedRamp. More recently, we added granular instance sizing, a PostgreSQL interface, and free trial instances to lower the barrier to entry for Spanner, and make it accessible for any developer and for any application, big or small.Speaking of small, one of the interesting things we discovered along the way is that Spanner isn’t only a great fit for huge mission-critical applications – we also use it internally for smaller applications and internal tools, secure in the knowledge that the data is safe, available, and nowhere near any limits. That’s the thing about infrastructure innovations: at their best, they aren’t only about scale, they’re about extracting complexity from applications and presenting the solution in an easy-to-use package.As we have incorporated solutions to those problems into Spanner, customers have dramatically simplified their applications. For example, application teams often created a dedicated “storage” tier to provide higher level features like indexes, transactions, or data synchronization needed to support their business logic. Spanner enables application teams to hollow out or even completely eliminate these tiers for significant cost and maintenance savings. We have also seen big reliability dividends: rather than each application discovering the corner cases of transactions, consistency or high availability architectures one at a time, Spanner’s customers are all able to benefit from a rigorously designed and battle-tested implementation out of the gate.