MongoDB or PostgreSQL? Choosing based on your data's shape

A developer who uses both databases in their projects says the right choice depends on how the data is structured. They favor PostgreSQL for highly relational data such as users, orders, payments, and invoices. MongoDB suits flexible or frequently changing data like content, logs, and product catalogs. A common mistake is picking MongoDB for its perceived ease, which can cause problems later when relationships between data must be managed. The author argues neither database is inherently better, and that using both in one project can be sensible.