The dual-write problem arises when a system uses both SpiceDB for authorization and an application database, leading to inconsistencies between the two. To address this issue, various approaches can be taken, including doing nothing, out-of-band consistency checking, making SpiceDB the source of truth, event sourcing, command-query responsibility segregation (CQRS), durable execution environments, and transactional outbox patterns. Each approach has its advantages and disadvantages, and the choice depends on the system's shape, domain requirements, and organizational appetite for change. Centralizing data required for authorization decisions can lead to big wins in consistency, performance, and safety, but it requires effort.