Do you have experience writing complex and optimized SQL queries without using ORM?

Yes, experience in writing complex and optimized SQL queries without using ORM is often necessary to improve performance and flexibility when working with databases.

For example, you can write a query with multiple JOINs, subqueries, and filtering conditions:

SELECT u.id, u.name, COUNT(o.id) AS orders_count
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
WHERE u.status = 'active'
GROUP BY u.id, u.name
HAVING COUNT(o.id) > 5
ORDER BY orders_count DESC
LIMIT 10;

This query allows you to retrieve the top 10 active users with more than 5 orders, which is difficult or inefficient to implement through ORM without losing performance.

Optimization includes using indexes, minimizing subqueries, and proper use of JOINs and filters.