In a technical talk hosted by AuthZed, Canva software engineer Artie Shevchenko delves into solving the dual-write problem in centralized authorization systems, particularly focusing on the use of SpiceDB. The dual-write issue arises when data must be replicated between a main database (like Postgres or Spanner) and SpiceDB, potentially leading to inconsistencies due to network failures, race conditions, and system bugs. These inconsistencies can manifest as false negatives or false positives, impacting data integrity and security. Shevchenko highlights that centralized systems like SpiceDB simplify the replication process by offering greater control over data management, reducing the volume of replication, and allowing for more straightforward handling of relationships and booleans. The talk explores various solutions, such as cron sync jobs and transactional outboxes, drawing on Shevchenko's experiences at Google and Canva. He emphasizes that while dual-write is an inherent challenge in data replication, SpiceDB's approach makes it more manageable by providing clear ownership and control over the authorization data replication process.