What experience do you have with MySQL database management systems in commercial projects?

In commercial projects using PHP and MySQL, I worked with databases for storing and processing user data, orders, products, and other entities. My experience includes:

• Designing and optimizing table structures considering normalization and indexes.
• Writing complex SQL queries for data retrieval, updating, and deletion.
• Using prepared statements to protect against SQL injection.
• Integrating MySQL with PHP through PDO and MySQLi extensions.
• Setting up transactions to ensure data integrity.
• Query optimization and performance analysis using EXPLAIN.
• Implementing migrations and database backups.

For example, in an online store, I implemented cart functionality and checkout processes, actively interacting with MySQL to save user state and process payments.