PlanetScale branching: preview databases, connection strings, and CORS when SPAs point at staging APIs

Some MySQL features differ on serverless branches—integration tests should assert both SQL and HTTP layers.

Foreign key modes may affect ORM migrations that indirectly influence API responses.

PlanetScale insights show query latency; correlate spikes with CORS-heavy user flows in RUM.

Export slow query logs before dropping a branch to preserve forensic evidence.