What databases or other data storage systems have you worked with? What is the RPS (requests per second) for write and read?

I have worked with various databases, including relational (PostgreSQL, MySQL) and NoSQL (MongoDB, Redis). In high-load projects, I optimized queries and architecture to ensure high performance. For example, in one project, the system handled up to 10,000 RPS for reads and about 2,000 RPS for writes, using caching and data sharding. It is important to consider the specifics of the load and choose appropriate scaling solutions.