Michelle Gienow discusses the challenges and drawbacks of sharding databases, particularly with PostgreSQL, arguing that it is not a sustainable solution for businesses needing scalability. Sharding, which involves dividing a database into smaller, manageable pieces, introduces significant complexity and operational overhead, requiring extensive manual coding and repeated interventions whenever changes are needed. This complexity leads to increased costs, slower development speeds, and heightened risks, as developers must constantly adjust application logic to accommodate the sharded structure. Gienow suggests that businesses should consider distributed SQL databases, like Spanner or CockroachDB, which inherently manage horizontal scaling and reduce the burdens associated with manual sharding. These modern databases offer built-in solutions for consistency, reliability, and scalability, freeing developers from costly and time-consuming manual processes and allowing businesses to adapt more flexibly to changing demands.