What databases have you worked with besides PostgreSQL?

In addition to PostgreSQL, I have worked with several other databases:

• MySQL: used in projects with a traditional relational model, for high-load web applications.
• MongoDB: employed for storing unstructured data and documents, when a flexible schema was required.
• Oracle DB: had experience working with large corporate systems that required high reliability and scalability.
• Redis: used as an in-memory storage for caching and session management.

Each of these databases was used depending on the project requirements, which allowed choosing the optimal solution for a specific task.