What database management systems have you used?

In working with Node.js, I used various database management systems (DBMS), depending on the task:

• PostgreSQL: A relational DBMS supporting complex queries and transactions. Used with libraries pg and ORM Sequelize.
• MySQL/MariaDB: A popular relational DBMS, used for projects with a classic data structure.
• MongoDB: A document-oriented NoSQL database, used with the mongoose driver for flexible work with JSON-like documents.
• Redis: A key-value store, used for caching and session storage.

Each of these DBMS has its advantages and is suitable for different scenarios — from complex transactional systems to flexible data storage without a strict schema.