Have you had experience using transactions in your projects?

Yes, in Node.js projects I have used transactions, especially when working with databases such as PostgreSQL or MySQL. Transactions allow grouping multiple operations into a single atomic unit, so that either all changes are applied or none are, which is important for maintaining data integrity.

Example of using a transaction with the pg library for PostgreSQL:

const { Client } = require('pg');

async function performTransaction() {
  const client = new Client();
  await client.connect();
  try {
    await client.query('BEGIN');
    await client.query('INSERT INTO users(name) VALUES($1)', ['Alice']);
    await client.query('INSERT INTO accounts(user_id, balance) VALUES($1, $2)', [1, 100]);
    await client.query('COMMIT');
  } catch (e) {
    await client.query('ROLLBACK');
    throw e;
  } finally {
    await client.end();
  }
}

Thus, if one operation fails, all changes will be rolled back.