Database transactions ensure multiple operations succeed or fail together. EF Core wraps SaveChanges in an implicit transaction, with explicit transactions and savepoints for more complex flows.

You do not need a class library per layer to follow Clean Architecture. One ASP.NET Core project, clear namespaces and NsDepCop or architecture tests can enforce the same dependency rules as a multi-project solution.

EF Extensions offers many bulk operation options, from insert behavior and column mapping to update rules, graphs, batching, synchronization, auditing and transactions.