A shopping cart must accept "add item" even during a network partition or when a database node is down. Which design fits?

Options

• ✗ One SQL primary with synchronous replicas
• ✗ A Raft group per cart
• ✓ Leaderless replication with versioned carts merged on read Correct
• ✗ Two-phase commit between the cart replicas

Why

The requirement picks availability over consistency (AP). Any replica takes the add, concurrent versions are kept and merged (union of items), and the cost is that a removed item can occasionally reappear.

Review this in your daily deck → All cards in Consistency