How are you doing with SQL and information interactions (integrations)?

I am confident in working with SQL, able to write complex queries including JOINs, subqueries, aggregations, and window functions. I am familiar with query optimization and indexing to improve performance.

Regarding information interactions, I have experience integrating systems via APIs, exchanging data in JSON and XML formats, and working with message queues (e.g., RabbitMQ, Kafka). I understand the principles of building ETL processes and synchronizing data between different systems.

An example of a simple SQL query to select users with orders:

SELECT u.id, u.name, COUNT(o.id) AS orders_count
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
GROUP BY u.id, u.name
HAVING COUNT(o.id) > 0;