Let's discuss your experience with non-relational data storage systems.

Non-relational data storage systems (NoSQL) are used for storing and processing data that do not fit into the traditional relational model. They are well-suited for large volumes of data, high write speeds, and flexible structures.

Main types of NoSQL databases:

• Document-based (e.g., MongoDB) — store data in JSON-like documents.
• Key-value (e.g., Redis) — simple key-value pairs for quick access.
• Columnar (e.g., Cassandra) — optimized for working with large volumes of data by columns.
• Graph (e.g., Neo4j) — for storing and analyzing graphs and relationships.

In my experience, I used MongoDB for storing dynamically changing data, where the document structure could differ, which was difficult to implement in a relational database. I also used Redis for caching and quick access to user sessions.

Using NoSQL allows increasing scalability and flexibility of applications, especially in distributed systems and when working with big data.