How did you organize data separation in your last project?

In my last project, a sharding strategy based on the user key was used to partition data in the database. This meant that each user's data was stored in a separate shard, which helped distribute the load and improve performance. Schemes with date-based partitioning were also used for logs and archival data to speed up queries and simplify storage management. This approach helps scale the system and provides data isolation for enhanced security.